国家开放大学电大《高级英语阅读(1)》《机电控制工程基础》网络课形考网考作业(合集)答案
国家开放大学电大《高级英语阅读(1)》《机电控制工程基础》网络课形考网考作业(合集)答案 《高级英语阅读(1)》网络课答案 形考任务一(70分) Chapter 1 Exercise(分值7分) 题目1 I. Vocabulary skills(3 points) Look at the columns below. Match each vocabulary word on the right with the correct definition on the left. (0.5 points each) 1.the bus or subway 2.proof of completion of courses of students 3.money for students from scholarships, grants, or loans 4.formal talks by professors or instructors on subjects of study 5.courses by video, video conferencing, or computers to students in different places 6.the points or grade a student gets on a test 答案:
II. Reading Comprehension (4 points) Read the passages, then answer the questions that follow. (1 point each ) Experiencing Culture Shock A When Eliza James arrived at the University of Xian, she was excited to live in a new country, to improve her Chinese, and to experience a culture so different from her own. But soon her excitement turned to frustration as she encountered one roadblock after another. “I felt like I couldn't accomplish anything. My dorm room had no heat, I couldn't get into the classes I wanted, and every time I asked someone for help they gave me the runaround. I felt like no one was listening to me.“ Eliza met with administrators, sent letters of complaint, and even contacted the consulate in Beijing, but she got nowhere. What Eliza didn't realize was that her American approach to solving problems was very different from the Chinese one in which patience and negotiation skills are key. She soon learned how to solve problems within the cultural norms of Chinese society instead of forcing her own values onto those around her. “I finally feel like I fit in and that I know what I'm doing. In fact, it's really fun being in a place that's so incredibly different from what I am accustomed to.“ B Yoshi Yamamoto is a junior at a small college outside of Boston. Although he is an honors student now, Yoshi didn't always have such an easy time studying in America. “Teaching methods are very different here than they are in Japan. It took me a long time to get used to learning in seminars and discussing ideas with my classmates. At first it seemed like I wasn't actually learning anything.“ Yoshi's reaction was to totally withdraw: he didn't participate in class discussion; he spent lots of time alone in his room, and he even skipped class on occasion. “I thought I could teach myself. Now I recognize the value of the U.S. academic system, and I am able to adapt it to my own learning style.“ C Both Eliza and Yoshi experienced what is called culture shock: psychological disorientation due to living in a new culture. For many international students, studying abroad can offer exposure to new cultures and an opportunity to study new fields and languages. However, it also offers the greater challenge of trying to function in a foreign culture. Studying and reading about a certain culture is poor preparation for the reality of living in it. According to psychological studies, the four stages of culture shock are 1. euphoria, 2. hostility, 3. gradual adjustment, and 4. adaptation. Culture shock can be manifested in many ways: homesickness, boredom, stereotyping of or hostility towards the host culture, overeating or overdrinking, withdrawal, and inability to work effectively. D Different people experience different levels of culture shock and react in different ways. For example, Eliza got angry while Yoshi withdrew from society. The most important thing to remember is that culture shock is normal; it is not something to be ashamed of. Luckily, there are some things international students can do to make their adjustment to a new country go more smoothly. For instance, they can stay in touch with family and friends from home, join international student organizations, meet people from their own countries, and get involved in campus activities. Most importantly, they can adjust to life abroad by keeping a sense of humor and trying to remain positive. Recognizing Paragraph Topics(choose the paragraph letter) 题目2 7. an explanation of culture shock 选择一项:
A. A B. B C. C D. D 题目3 8. ways that students can adjust to living in a new country 选择一项:
A. A B. B C. C D. D 题目4 9. the experience of an international student in the United States 选择一项:
A. A B. B C. C D. D 题目5 10. the experience of an international student in China 选择一项:
A. A B. B C. C D. D Chapter 2 Exercise(分值7分) 题目1 I. Vocabulary Skills(2 points) Sometimes examples can explain the meaning of a word or phrase. For example, sun, rain, and wind are examples of kinds of weather. Look at the columns below. Match each vocabulary word or phrase in the first column with the examples in the second column. (0.4 points each) 1.kinds of extreme weather 2.Earth’s natural materials and gases 3. diseases or health disorders 4. seasons of the year 5. natural areas or regions of the earth 答案:
II. Reading Comprehension (5 points) Complete the following statements by choosing the best from the answers A, B or C. (1 point each) Seasonal Affective Disorder: More than Just the Blues A Joshua dreads the winter months, not only because of the cold New England weather--the sleet, snow, wind, and rain--but because as the seasons change from summer to fall to winter, the days get shorter. As the days get shorter, he starts feeling depressed and irritable and spends more and more time at home, eating and sleeping. A graduate student in philosophy, Joshua finds that he gets little work done during the winter months and has trouble paying attention in class and concentrating on his research. “I soon realized that what I thought was just the 'winter blues' was something more extreme than that.“ Josh visited a doctor who diagnosed him with SAD. B Seasonal Affective Disorder, or SAD, is a kind of depression that occurs seasonally. It is associated with the long hours of darkness and lack of sunlight during the winter months (people with SAD usually feel worse from December through February). Scientists don't completely understand the exact causes of SAD, but they believe it is related to a biochemical imbalance in the hypothalamus. The hypothalamus is the basic part of the brain that controls the body's breathing, heartbeat, metabolism, and hormone release. The effects of SAD include moodiness, irritability, low energy, increased appetite for carbohydrates (foods such as potatoes, rice, and bread), difficulty concentrating, and the tendency to oversleep. C Although doctors described SAD for the first time in 1984, humans have probably dealt with the disorder for thousands of years. It is not a coincidence that many cultures have important celebrations during the short days of the winter months. Christmas, Hanukkah, and Winter Solstice celebrations all occur in December. These celebrations involve lighting candles in order to bring light, warmth, and happiness to an otherwise depressing time of year. D So what can SAD sufferers do to feel better? Naturally, they need more light. For people who have mild cases of SAD, exercising in the morning sun could be enough to help them. Phototherapy, or light therapy, is usually prescribed for people who have more serious cases of the disorder. In light therapy, patients sit in front of a light box, a strong artificial light, for up to four hours a day. Phototherapy is effective in over 80% of SAD cases, and patients usually see results within three to four days. Although the symptoms of SAD are similar to those of clinical depression, traditional antidepressants have not proven useful in treating SAD. While psychological counseling cannot treat the symptoms of SAD, it is recommended to help SAD sufferers learn to accept and deal with their illness. 题目2 6. Joshua starts feeling depressed and irritable in the winter because 选择一项:
A. he gets little work done B. he suffers from Seasonal Affective Disorder C. he is a graduate student in philosophy 题目3 7. Seasonal Affective Disorder, or SAD, is a condition that researchers believe affects people during the winter months. Scientists believe it is caused by 选择一项:
A. breathing, heartbeat, metabolism, and hormone release B. moodiness, irritability, loss of energy, increased appetite, difficulty concentrating, and sleepiness C. lack of sunlight and a biochemical imbalance in the brain 题目4 8. Humans have probably struggled with SAD since 选择一项:
A. ancient times B. December C. 1984 题目5 9. People who suffer from SAD can to feel better. 选择一项:
A. do light therapy B. take antidepressant drugs C. eat carbohydrates 题目6 10. This passage talks about_____. 选择一项:
A. what the SAD effects are B. Both A and B. C. how to help SAD suffers Chapter 3 Exercise(分值7分) I. Reading Comprehension (5 points) Read the passages, then answer the questions that follow. (1 point each ) Fast food can be good food Many people are too busy to prepare and eat three nutritious meals a day.so they turn to the convenience of fast-food restaurants. Many of the items at fast-food restaurants, snack bars, and food stands are fattening and not very nutritious.But fast food doesn’t have to be unhealthy.you can eat at fast-food restaurants and still eat well. Pay Attention to Calories and Fat Content By paying attention to the number of calories and fat that a food item has ,you can make smarter choices.Calories are “units for measuring how much energy a food will produce”.condsider two fast-food meals. A quarter-pound hamburger with cheese, jumbo-size fries,and a 16-ounce soda have a total of 1,535 calories and 76 grams of fat .a broiled (cooked under direct heat or over a flame )chicken sandwich ,a side salad with low-fat dressing,and a glass of water at the same fast-food restaurant have only 422 calories and 7 grams of fat .but maybe you really want a hamburger and fries .well,you can have a small hamburger,a small serving of fries,and a glass of water.At a total of 490 calories and 20 grams of fat,that’s still a much smarter choice than the large burger ,fries,and 20 grams of fat ,that’s still a much smarter choice than the large burger,fries,and sada. There’s More That You Can Do There are a few additional things you can do to make sure you eat well in fast food restaurantS.First of all,say “no” when the cashier asks you if you want to “supersize” you meal (order an extra large portion of each item).Second, ask for no mayonnaise or sauce,or ask for it on the side (in a separate dish).Third,substitute(use something instead of something else)healthy foods for fatty ones. For example,instead of ordering deep-fried tempura,order fresh vegetables.Instead of ordering a beef burrito with lots of cheese and sour cream,order a vegetable burrito with beans and rice.and don’t eat the chips!Another thing you can do is order a side salad or a vegetable soup and eat it first.That way,you will eat some vegetables,and you won’t be able to eat as much of your burger and fries.Fnally,eat slowly and stop eating when you’re full. It sounds simple,but many people keep eating even after they become full. 题目1 1.What is the main idea of this article ?________ 选择一项:
A. It’s smart to eat foods with low calories and fat content. B. Fast food is always bad for you . C. You can eat well in fast-food restaurant D. Fast-food restaurants are the best the place to find healthy foods . 题目2 2.A small hamburger and small firies has __________ 选择一项:
A. more calories and fat than a chicken sandwich and a salad. B. the same amount of calories and fat as a chicken sandwich and a salad. C. fewer calories and fat than a chicken sandwich and a salad. D. the same amount of calories and fat as a large portion of fries. 题目3 3.Some things you can do to eat well in fast-food restaurants are________ 选择一项:
A. ask for eatra manyonnaise and sauce and say no to “surpersizing” . B. order a vegetable burrito instead of chips and eat sour cream . C. order smaller portions and eat all the food you order. D. order healthy foods instead of fatty ones and drink water. 题目4 4.Manyonnaise and sauces probably_________ 选择一项:
A. make you eat less because they make you feel full sooner. B. make you eat more because they make your food taste better. C. have a lot of fat and calories. D. don’t have a lot of fat and calories. 题目5 5. By eating a salad or soup before the rest of your meal,_______ 选择一项:
A. you eat less of the rest of your meal. B. you eat more slowly. C. you get full sooner. D. you eat the rest of your meal more quickly. II. Vocabulary skills(2 points) Read the paragraph below and fill in each blank with a word from the box. (0.4 points each) 题目6 changes damaging losing global available The growing similarities in diet and eating habits around the world are influencing people of various cultures in different ways. For example, Western foods are 6 damaging health in the industrialized island country of Japan. Instead of small meals of seafood, rice, and vegetables, the typical Japanese diet now includes large amounts of meat, dairy products, and desserts like tiramisu, a rich Italian dish full of chocolate, cheese, and sugar. According to Japanese health researchers, such 7 changes in eating habits are related to a great increase in health problems such as heart disease, strokes, cancer, and diabetes. On the other hand, the changing 8 global diet is having the opposite effect on the people in the CzechRepublic. The government of this European nation no longer supports meat and dairy products financially, so the cost of these foods is going up. In contrast, fresh fruits and vegetables are becoming more widely 9 available from private markets and stands. Cooks are even serving salads to schoolchildren, and families are eating healthier home-cooked meals. For these reasons, fewer Czech men are having heart attacks, the women are 10 losing a lot of weight, and most people are living healthier lives. Chapter 4 Exercise(分值7分 I. Vocabulary Skills(2 points) 题目1 Match each vocabulary word on the left with the correct definition on the right. (0.4 points each) 1.make sense 2.pedestrians 3.vehicle 4.teenager 5.fine 答案:
II. Reading Comprehension (5 points) Complete the following statements by choosing the best from the answers A, B, C, or D. (1 point each) These days, it’s getting easier and easier to find your way around. Some people have GPS devices in their cars to make sure they don’t get lost. GPS stands for Global Positioning System. These devices use satellites in space to “see” where you are and give you directions to where you want to go. And if you don’t have a GPS device, you can simply go online to get step-by-step directions. Websites like MapQuest.com and mappoint.msn.com can produce a map and directions in just a few seconds. But how do they do it? MapQuest® uses data (information) from a few different sources to produce directions and maps. Before MapQuest® went online, it sold regular paper maps in places like gas stations. The website uses the data from those paper maps, information from digital mapping companies, and government databases. At the moment, MapQuest® uses more than 30 computers to read all this data and provides users with millions of maps every day. In order to find the best route (way or path) from one place to another, MapQuest® first has to look at all possible routes. Then MapQuest® looks at each part of each possible route. It considers the types of roads on the different routes. Are they dirt roads, paved roads, freeways, or city streets? It looks at how many turns there are in each route and what kinds of turns they are. Are they right turns or left turns? It also considers the speed limit on each road and how many intersections there are. An intersection is “a place where two or more roads cross each other”. MapQuest® can also tell you how long your trip will take you. It does this by doing some math. MapQuest® bases its estimated driving times on the length and speed limit of each part of the route and the amount of time it probably takes to get through each intersection. For example, it allows more time for a left turn at an intersection than it does for a right turn. Someday, maybe we will have cars that can just drive us wherever we want to go, but for now, mapping websites make it a little harder to get lost. 题目2 6.What is the main idea of this article? 选择一项:
A. Why mapping websites don’t work well. B. Why mapping websites are better than paper maps. C. How mapping websites work. D. How the first mapping website started. 题目3 7.According to the article, MapQuest®______ 选择一项:
A. started as maker of government databases. B. started as an Internet company. C. uses millions of computers to read data. D. starting by selling paper maps. 题目4 8.When you search for directions, the first thing MapQuest® does is_______ 选择一项:
A. consider how many turns you want to take. B. print out a map and directions. C. estimate driving time. D. look at all possible paths. 题目5 9.When it’s deciding on the best route, MapQuest® probably chooses ________ 选择一项:
A. the route with the most turns. B. dirt roads instead of paved roads. C. freeways instead of dirt roads. D. city streets instead of freeways. 题目6 10. To estimate your driving time, MapQuest® considers _________ 选择一项:
A. the distance between turns on your route. B. the speed limit for half of the route. C. the fastest and slowest speed limits on your route. D. the speed limits and types of turns on your route. Chapter 5 Exercise(分值7分) I. Reading Comprehension (5 points) Read the five main-idea questions that follow about the information in the reading. Three details correctly answer each question. Cross out the untrue, unrelated detail. (1 point each ) 题目1 1. What are the definitions of the two main types of families? 选择一项:
A. Human beings lived in loosely-related groups. Each group had a common ancestor long time ago. B. The nuclear family consists of two parents and their biological or adopted children. C. The extended family may include grandparents, parents, children and relatives living together on the same street or in the same area. D. The nuclear family is the same as the extended family. 题目2 2. What are the reasons for the changes in the structure of the family? 选择一项:
A. The divorce rate went down and the birthrate began to rise in the early 1900s in the United States. B. Couples did not want many children then. C. In the early 1900s in the United States, the divorce rated went down and the birthrate went down. D. At that time, couples were staying married for few years. 题目3 3. What happened to families in industrialized countries in the 1930s and 1940s? 选择一项:
A. Before and during World War II, families faced few financial problems and women didn’t have to work away from home. B. Men were at war, so women had to work outside the home. C. Before and during World War II, families had problems. D. Families had serious financial problems during World War II. 题目4 4. What changes will happen to family structure during the next decades? 选择一项:
A. Divorces would be fewer, mothers would stay at home after the war. B. Children began living at home longer. C. After the war, family structure changed back. D. After the war, there were more divorces and fewer stay-home-mothers. 题目5 5. What will families be like in the future? 选择一项:
A. Many people want the traditional two-parent family back. B. Two-parent family will probably come back and all other family forms will end. C. Unmarried parents with adopted or foster children, and one-person households. D. There may be more single-parent families. II. Vocabulary Skills(2 points) Read the paragraph below and fill in each blank with a word from the box. ( 0.4 points each) 题目6 living extended category typical believe The Family of the Future Many people today would like the traditional two-parent family back—that is to say, they want a man and a woman to marry for life; they also think the man should sport the family and the woman should stay home with the children. However, few families now fall into this 6 category In fact, if more women decide to have children on their own, the single-parent household may become more 7 typical than the traditional family in many countries. Also, unmarried couples may decided to have more children—or they might take in foster children or adopt. And because people are staying single and 8 living longer (often as widows), there may be more one-person households in the future. On the other hand, some people 9 believe similar events happen again and again in history. If this is true, people may go back to the traditional 10 extended or nuclear family of the past. Others think the only certainty in history is changing: in other words, the structure of the future family could begin to change faster and faster—and in more and more ways. Chapter 6 Exercise(分值7分) I. Vocabulary skills(2 points) Complete the following statements by choosing the best from the answers A, B, C, or D. (0.4 points each) 题目1 1. Some examples of the architecture of old Europe are the magnificent cathedrals and castles. The design and building styles of modern architecture are excellent too. What does the noun architecture mean in these sentences? 选择一项:
A. the place with significant civilization everywhere B. people that study the culture of old Europe and other societies C. the art and science of designing the study of classical literature D. the form and plan of buildings and other structures 题目2 2. Perhaps the real beginning of civilization—with its scientific and technological discoveries and inventions—was in the Middle East and Africa. Over five thousand years ago, those ancient civilizations had astronomy, mathematics, medicine, government, and so on. Which word is a synonym of the word civilization? 选择一项:
A. technology B. cathedral C. culture D. astronomy 题目3 3. The cultural legacy of ancient Chinese and Indian peoples included walled cities, the first governments, tools for work, and weapons for protection. odern peoples built on this legacy.What is a possible explanation of the word legacy? 选择一项:
A. ideas and achievements passed from earlier generations to modern society B. a gift of money that somebody gives to another person C. international business conducted in cities and government structures D. the state or condition of being legal; not against the law 题目4 4. “For me, the idea of ancient culture creates a contradiction in definitions,” said Karen, going against Mei’s views. “Only modern things can be part of culture.Of course, people that like classical art and music will contradict me.” What might the noun contradiction mean? 选择一项:
A. the opposition of two opinions B. wearing a Hawaiian shirt in an ancient culture C. the short forms of two words together D. to put words together 题目5 5. Because of the worldwide media—movies, TV, CDs, the Internet, newspapers, magazines—everybody knows the same information, plays the same music, and enjoys the same jokes.How might you define the phrase the media? 选择一项:
A. the combination of visual, sound, and printed ways to send ideas around the world B. communication styles include motions, gestures and facial expressions C. the tradition of being in the middle—not on the extremes of possible views D. events that appear in the daily news and that everyone knows about II.Reading Comprehension (5 points) Decide whether the following statements are true or false. Write “T” for True and “F” for False. (1 point each) 题目6 Many visitors to different countries don’t realize how important it is to understand a country’s culture. Sometimes people learn this lesson by making a big cross-cultural blunder, or embarrassing mistake. In business situations, these blunders can cost a lot of money or end business relationships. 6.It is important to understand other people’s cultures before you do business with them. 选择一项:
A. F B. T 题目7 For example, one company wanted to sell toothpaste in Southeast Asia. In their advertisements, they claimed that their toothpaste whitens teeth. They didn’t understand that many of the local people chewed betel nuts to make their teeth black, and that these people thought black teeth were attractive. 7. The toothpaste company probably kept using the same advertisement in Southeast Asia. 选择一项:
A. F B. T 题目8 In another case, a car company tried to sell a car called “Matador” in a Spanish-speaking country. The company thought that it was a strong name because it means “bullfighter”. In Spanish, matador is indeed a noun meaning “bullfighter”. But it is also an adjective meaning “killing”. Imagine driving around in a car called “Killing”! 8. The car company that tried to sell a car to a Spanish-speaking country probably didn’t sell many Matador cars in that country. 选择一项:
A. F B. T 题目9 A European businessman had an important meeting with a company in Taiwan. He wanted to bring gifts for the people he was meeting with. He thought that something with his company’s logo on it would be a nice gift. So he bought some very nice pocket knives and had his company’s logo printed on them. He didn’t know that giving a knife as a gift symbolizes cutting off a friendship! 9. The European businessman probably researches new cultures before he visits them now. 选择一项:
A. T B. F 题目10 It’s very easy to make blunders like these people did. But it’s also very easy not to. Before you visit a new country, research that country’s customs and etiquette (social rules for polite behavior). You can find a lot of information online. Just go to a search engine and type in key words like “cross-cultural etiquette” or “cultural information Taiwan”. By spending a few minutes doing research, you can save yourself from a lot of embarrassment and make sure you don’t accidentally offend anyone. 10. What you can disagree with people to save yourself from making cross-cultural blunders. 选择一项:
A. T B. F Chapter 7 Exercise(分值7分) I. Reading Comprehension (5 points) Decide whether the following statements are true or false. Write “T” for True and “F” for False on the Answer Sheet. (1 point each) 题目1 For instance, a doctor doesn’t always have time to thoroughly explain an illness. In these cases, the Internet can be a valuable resource—a place to read all about the causes, symptoms, and remedies for an illness. 1. One benefit of using the Internet as a medical resource is it has a lot of information about illnesses and diseases. 选择一项:
A. F B. T 题目2 For example, some websites claim that sniffing (smelling) a newspaper can cure nausea (the feeling of being sick to your stomach and wanting to vomit). 2. One possible remedy for nausea is drinking a lot of tea. 选择一项:
A. T B. F 题目3 Other websites suggest that a person with a cold should keep a piece of raw garlic in his or her mouth all day and bite down on it every few minutes to release the juice. People with smelly feet are told to soak their feet in tea for half an hour. 3. The websites remedies might be unpleasant or odd, but they probably will cause harm. And who knows? They might actually be unhelpful. 选择一项:
A. F B. T 题目4 An herbal remedy for helping your memory may also be a blood thinner. So if your doctor prescribed (put you on) a blood thinner and you start taking this herb without asking your doctor about it, a simple cut could be deadly; you might not be able to stop bleeding. 4. A person who is taking a prescribed drug should probably talk to the doctor before taking an herbal remedy. 选择一项:
A. F B. T 题目5 The bottom line is this: be careful when using the Internet as a health resource. Use it to find information that you can discuss with your doctor. But don’t spend a lot of money on “miracle cures”. 5. The best way to use the Internet as a medical resource is to read about your illness and discuss what you find out with your doctor. 选择一项:
A. T B. F II. Vocabulary skills(2 points) Read the paragraph below and fill in each blank with a word from the box. ( 0.4 points each) 题目6 disease substance classification prevent figure In a small-town farm market, hundreds of elderly people drink a glass of sour dark cherry juice every day. These happy senior citizens, some of them over the age of 90, claim that the natural fruit juice cures—or at least decreases—the pain of their arthritis, a 6 disease of the joints of the aging body. It’s a folk remedy, not a proven medical therapy. Nevertheless, science is beginning to 7 figure out why sour cherry juice might work to improve the health of patients with arthritis. The secret is in the 8 substance that gives the cherries their dark red color. It belongs to a 9 classification of natural nutrients that color blueberries, strawberries, plums, and other fruits—and vegetables too. Moreover, these coloring substances may help to 10 prevent serious health disorders like heart disease and cancer. In other words, vitamins and fiber are not the only reasons to eat fruits and vegetables. “To take advantage of natural whole foods,” advise nutritionists. Chapter 8 Exercise(分值7分) I. Vocabulary Skills(2 points) Complete the following statements by choosing the best from the answers A, B, C, or D. ( 0.4 points each) 题目1 1.At all hours, the media offer language learners “real-life” audio visual instruction and practice in aural comprehension. 选择一项:
A. hospital and health information B. understanding spoken language C. the answers to test questions D. real-life experience 题目2 2. High-quality TV programming —a good plan of shows about various fields of study—can increase people’s knowledge and improve their thinking abilities. 选择一项:
A. scientific and medical shows B. movies with good music C. academic lecture courses D. choice and organization of shows 题目3 3. Television and video provide almost everyone with good entertainment—a pleasant way to relax and spend free time at home. 选择一项:
A. amusement or pleasure B. freedom from worry and tension C. relaxation through exercise D. fun through serious study 题目4 4. Images of violence on the screen scare people, giving them terrible nightmares when they sleep. 选择一项:
A. dark, stormy weather B. bad conditions C. physical disabilities D. behavior that hurts people 题目5 5. The talk shows of “trash TV” make instant “stars” of real people with strange or immoral ideas, who tell their most personal secrets, shout angrily, and attack one another. 选择一项:
A. valuable programs B. negative effects C. shows without quality D. normal life stories II. Reading Comprehension (5 points) Complete the following sentences by choosing the best from the answers A, B, C, or D. (1 point each) A Everyone makes mistakes, or so the saying goes. But have you ever heard about mistakes in Hollywood? When most people think of Hollywood, they think of blockbusters (very successful movies), high-paid actors, glitz, and glamour. But according to one Website, many Hollywood movies are full of mistakes. Some are technical errors. For instance, in a scene of the science-fiction adventure film The Matrix, when the main character steps out of his car, the viewer can clearly see the camera crew in the car window. In another scene, the same character is typing on his computer, yet the computer screen is blank. Other movie mistakes are historical. For example, the epic Gladiator, an Oscar winner, is known for having lots of historical errors. Throughout the movie, the gladiator Maximus refers to his home in Spain, and the other characters call him “the Spaniard.“ However, in 180 A.D., when the movie takes place, Spain as a country or even as a concept didn't exist yet. At another point in the movie, Maximus says that his homeland of Spain has “the best horses.“ But horses weren't brought to the Iberian Peninsula until the invasion of the Moors (North Africans) in 711 A.D, more than 500 years after the movie takes place. The historical drama Titanic, another Oscar winner, also has its share of historical blunders. The Titanic sunk in the year 1912. So why is one of the characters wearing a digital watch? In fact, movie watchers have found over 100 mistakes in The Matrix, Gladiator, and Titanic. Can you think of any errors in your favorite films? B How susceptible are you to advertising? Has a TV commercial or magazine ad ever made you buy the product that was advertised? If so, perhaps you have been subjected to subliminal advertising. Subliminal advertising is a kind of advertising that appeals to the subconscious. The word “subliminal“ comes from the Latin “sub“ meaning “lower,“ “beneath,“ or “under,“ and “limen“ meaning “threshold,“ (the level at which something begins to happen). Thus, subliminal advertising stimulates your brain at a level below conscious perception. You cannot see, hear, or perceive subliminal ads, but they may affect you just the same. There are two main types of subliminal ads. The first involves flashing messages quickly during a commercial or film. The messages appear and disappear so rapidly that the mind cannot process them consciously, but it might receive them passively, at a subconscious level. James Vicary, a market researcher, first introduced this kind of subliminal advertising in 1957 when he flashed the words “Eat Popcorn“ and “Drink Coca-Cola“ every five seconds during a movie. The messages couldn't be seen, yet Vicary claimed that the moviegoers' brains could perceive them: Coke sales went up by 18% and popcorn sales by over 50%. More recently, the same type of subliminal advertising was used in a negative ad for a political campaign. In the ad, the word “rats“ flashed up briefly during the part of the ad describing one party's healthcare plan. The purpose was to associate that opposing party with the negative word “rats.“ The second kind of subliminal advertising involves hiding or incorporating images into visual advertisements. A well-known example is on a package of a famous brand of cigarettes. Some say that if you look closely you can see the image of a man who is sexually aroused. In fact, a lot of subliminal advertising involves sex, coming from the idea that “sex sells.“ One media researcher claims that everything from crackers to alcohol to soda has used subliminal sexual imagery to appeal to buyers. Although studies show that consumers believe strongly in the power of subliminal ads, no one can prove the effects of subliminal advertising. Psychologists and others who study subliminal stimuli have not been able to show that subliminal advertising actually works. Many advertising researchers believe that traditional ads, in which a powerful image is used to sell a product, are more effective than subliminal advertising. All the same, it still remains a controversial topic, one that is on the mind of buyers and sellers alike. 题目6 6. What is the best title for the Paragraph A? 选择一项:
A. The Success of Hollywood: Movie Madness. B. Hollywood Bloopers: Mega Movie Mistakes. C. History or Hollywood? Hollywood Interprets Famous Historical Events. 题目7 7. What is the best title for the Paragraph B? 选择一项:
A. The Effect of Advertising on the Human Brain. B. Sex Sells: This History of Sex in Advertising. C. Subliminal Advertising: What Is It? Does It Work? 题目8 8.The Moors invaded Spain ______ the movie Gladiator takes place. 选择一项:
A. before B. after C. since 题目9 9. Another word for mistake is ______. 选择一项:
A. error B. blunder C. A and B 题目10 10.The subconscious is the part of the brain that _______. 选择一项:
A. passively notices and remembers information B. actively notices and remembers information C. does not notice or remember information Chapter 9 Exercise(分值7分) I. Vocabulary Skills(2 points) 题目1 Which of the words below contain a prefix with a negative meaning? Choose N. Choose X for the words without negative meanings. ( 0.4 points each) discourage 答案 N disrespect 答案 N illustrate 答案 X instant 答案 X illegal 答案 N II. Reading Comprehension (5 points) Complete the following statements by choosing the best from the answers A, B, C, or D. (1 point each) Meeting the Perfect Mate What is the best way to meet the perfect husband or wife? I am continuing to interview students on campus trying to answer this question for my sociology class. So far, people have mentioned arranged matches, discos and bars, computer dating services, and personal ads. One guy even said he thought supermarkets were the best places to meet women. I guess you can talk a lot about a head of lettuce! I decided to go to the school cafeteria to interview some people there. “I think date cafés are the best way to meet people,“ said my friend Rahul. “Date cafés? What's that?“ I asked. “Well, a date café is both a café and a dating service. You go to the café, order a cup of coffee or whatever you want, and look through people's profiles. Then, if someone interests you, you can send him or her an email and arrange a date at the café. You can also fill out your own profile and have people email you. The form asks you about everything from looks, to interests, to religion. The date café is a relaxed way to make contacts.“ “Are there many of them around?“ I asked. “Hmm. Well, there's one near campus called Drip. In fact, I had a Drip date just last week,“ said Rahul. “Drip! But isn't that a word that's used to describe someone who is dull and boring? It doesn't sound too promising.“ “Yeah, well it's funny you say that, because my date was pretty uninteresting. She barely talked at all, and she kept looking down at her coffee mug.“ “Well, what about a mail order bride?“ said Rahul's roommate, Joni. “A what?“ I asked. “A mail order bride. You know, you search for your wife in a catalog and the next thing you know you're married. With the Internet it's easier than ever,“ she said. “Ugh, that sounds awful.“ I said. “Have you ever met anyone who has done that?“ “Yes, my uncle did it. His marriage ended a year later. The truth is, I'm against it. Usually the women come from poor countries and don't know what they're getting into. My uncle's wife had a really hard time adjusting and went back to her country as soon as they split up.“ “I think mail order is out. Any other suggestions?“ “I find that meeting people through classes or extracurricular activities is a good idea,“ said Michelle. “For instance, I signed up for a Japanese cooking class, both because I like Japanese food, and because I thought I might meet someone nice with similar interests.“ “And did you?“ “Yeah, I made lots of friends: Sumi, Katrina, Mariah...no guys, though. The class was 90% women. In fact, now that you mention it, the same thing happened with the salsa class, the pottery class and my Tai Chi class. I met a lot of nice women, but I definitely did not find the man of my dreams.“ Last I interviewed a couple in the library. “Friends“ they said. “We met through friends. It's the best way to find the perfect mate.“ “Really,“ I said. “And why is that?“ “Well, your friends usually know what you like. And also, you know the person is someone you can trust, not like meeting someone in a bar or a supermarket. For instance, we met because Chris's lab partner thought we would really get along.“ “Yeah, Scott and I met, and I immediately liked him. I emailed him and it took him three months to email me back!“ “Well, I'm a little shy, but it eventually worked. Here we are, a year later and still together.“ “Well that's the best story I've heard yet, “ I said. But if I've learned one thing in this study, it's that meeting someone special, no matter how you do it, is difficult.“ 题目2 6.If you interview someone, you __. 选择一项:
A. ask him/her a lot of questions B. ask him/her to fill out a form 题目3 7. A person's profile probably __. 选择一项:
A. shows a picture of the person B. tells something about the person 题目4 8. A drip is __. 选择一项:
A. a kind of computer dating service B. a dull, boring person 题目5 9. If something is awful, it's __. 选择一项:
A. interesting and unusual B. unpleasant and bad 题目6 10. If you and your mate split up, you __. 选择一项:
A. end your relationship B. get engaged Chapter 10 Exercise(分值7分) I. Reading Comprehension (5 points) Decide whether the following statements are true or false. Choose “T” for True and “F” for False. (1 point each ) 题目1 Competition in Olympic sports is supposed to be fair. However, in judged sports, fairness is impossible. Therefore, judged sports should be banned from the Olympic games. A judged sport is any sport that requires judges to determine a winner. For example, gymnastics, figure skating, half pipe (snowboarding), and diving are all judged sports. 1.The writer believes judged sports should be eliminated from the Olympics. 选择一项:
A. T B. F 题目2 Why do I believe that judged sports should be eliminated from the Olympics? First of all, judges don’t see everything. For example, a mistake in figure skating can happen in a fraction of a second. If a judge blinks or looks away for a moment, he or she might miss the mistake and give the skater a higher score than the skater deserves. 2.One reason that judged sports should not be allowed in the Olympics is that judges can have different opinions. 选择一项:
A. T B. F 题目3 Second, two judges can disagree about which athlete gave the best performance. In sports in which the difference between gold and silver is usually a few hundredths of a point, this kind of subjectivity is unacceptable. Can anyone really say with certainty that a gymnast who receives a score of 9.825 is a better gymnast than one who scores 9.823? 3.One argument against banning judged sports from the Olympics is that people should stop arguing about it. 选择一项:
A. T B. F 题目4 A lot of people claim that judged sports are subjective and should not be allowed in the Olympics. They feel that only sports that are measured objectively for things like speed, such as swimming, track, and skiing, should be allowed because judges can’t be objective and fair. I disagree with these people. Why? I believe that no sport is 100% fair and objective. 4. The writer here believes all sports are objective. 选择一项:
A. T B. F 题目5 Some athletes may win because their equipment is better than their opponents’ equipment. For example, in the 2000 summer Olympics, some swimmers wore controversial high-tech suits. The maker of the suit claimed that the fabric could make a swimmer 3% faster. No one could prove that this was true, but they couldn’t prove that it wasn’t true either. 5. The equipment can be one reason that decides athletes’ sports scores. 选择一项:
A. T B. F 题目6 II. Vocabulary Skills(2 points) Match the following vocabulary items on left with their possible explanations on right. ( 0.4 points each) co-worker contribute promotion progress intermission 答案:
形考任务二(30分) 破冰行动(所属章:Guidelines;
分值5分;
需要教师批阅)讨论区 异国特色食谱(所属章:Chapter 3;
分值5分;
需要教师批阅)讨论区 身边的家庭模式(所属章:Chapter 5;
分值5分;
需要教师批阅)讨论区 新闻采访稿(所属章:Chapter 8;
分值5分;
需要教师批阅)互动评价 网上表现(所属章:所有章节;
分值10分;
需要教师批阅) 《机电控制工程基础》网络课答案 形考任务1 一、判断题(共20道,每道2分) 题目1 自动控制就是在人直接参与的情况下,利用控制装置使生产过程的输出量按照给定的规律运行或变化。
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对 错 题目2 反馈控制系统通常是指正反馈。
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对 错 题目3 所谓反馈控制系统就是的系统的输出必须全部返回到输入端。
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对 错 题目4 给定量的变化规律是事先不能确定的,而输出量能够准确、迅速的复现给定量,这样的系统称之为随动系统。
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对 错 题目5 自动控制技不能提高劳动生产率。
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对 错 题目6 对于一般的控制系统,当给定量或扰动量突然增加时,输出量的暂态过程一定是衰减振荡。
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对 错 题目7 对于一般的控制系统,当给定量或扰动量突然增加某一给定值时,输出量的暂态过程可能出现单调过程。
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对 错 题目8 被控制对象是指要求实现自动控制的机器、设备或生产过程。
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对 错 题目9 任何物理系统的特性,精确地说都是非线性的,但在误差允许范围内,可以将非线性特性线性化。
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对 错 题目10 自动控制中的基本的控制方式有开环控制、闭环控制和复合控制。
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对 错 题目11 一个动态环节的传递函数为1/s,则该环节为一个微分环节。
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对 错 题目12 控制系统的数学模型不仅和系统自身的结构参数有关,还和外输入有关。
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对 错 题目13 控制系统的传递函数取决于自身的结构与参数,和外输入无关。
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对 错 题目14 传递函数模型可以用来描述线性系统,也可以用来描述非线性系统。
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对 错 题目15 系统的传递函数为则该系统有两个极点。
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对 错 题目16 传递函数是物理系统的数学模型,但不能反映物理系统的性质,因而不同的物理系统能有相同的传递函数。
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对 错 题目17 某环节的输出量与输入量的关系为y(t)=Kx(t),K是一个常数,则称其为比例环节。
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对 错 题目18 对于同一系统,根据所研究问题的不同,可以选取不同的量作为输入量和输出量,所得到的传递函数模型是不同的。
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对 错 题目19 在零初始条件下,传递函数定义为输出和输入之比。
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对 错 题目20 控制系统传递函数分子中s的最高阶次表示系统的阶数。
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对 错 二、单项选择题(共20道,每道3分) 题目21 开环控制系统的精度主要取决于 。
选择一项:
A. 反馈元件 B. 放大元件 C. 校正元件 D. 系统的校准精度 题目22 反馈控制系统通常是指 。
选择一项:
A. 正反馈 B. 负反馈 C. 干扰反馈 D. 混合反馈 题目23 如果系统的输出端和输入端之间不存在反馈回路,这样的系统一定是 。
选择一项:
A. 开环控制系统 B. 正反馈环控制系统 C. 闭环控制系统 D. 复合反馈系统 题目24 输出端与输入端间存在反馈回路的系统一定是 。
选择一项:
A. 开环控制系统 B. 正反馈环控制系统 C. 闭环控制系统 D. 有差控制系统 题目25 数控机床系统是由程序输入设备、运算控制器和执行机构等组成,它属于以下 。
选择一项:
A. 恒值控制系统 B. 程序控制系统 C. 随动控制系统 D. 开环系统 题目26 是控制信号与主反馈信号之差。
选择一项:
A. 偏差信号 B. 误差信号 C. 输出信号 D. 干扰信号 题目27 是指系统输出量的实际值与希望值之差。
选择一项:
A. 偏差信号 B. 误差信号 C. 输出信号 D. 干扰信号 题目28 以下的给定量是一个恒值。
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A. 无静差系统 B. 有静差系统 C. 脉冲控制系统 D. 恒值控制系统 题目29 输入量为已知给定值的时间函数的控制系统被称为 。
选择一项:
A. 程序控制系统 B. 有静差系统 C. 脉冲控制系统 D. 恒值控制系统 题目30 是控制系统正常工作的首要条件,而且是最重要的条件。
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A. 平滑性 B. 快速性 C. 准确性 D. 稳定性 题目31 已知线性系统的输入为单位阶跃函数,系统传递函数为G(s),则输出Y(s)的正确表达式是 。
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题目32 传递函数表示 环节。
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A. 微分 B. 积分 C. 比例 D. 滞后 题目33 控制系统闭环传递函数的分母多项式的根称为该系统的 。
选择一项:
A. 开环极点 B. 闭环极点 C. 闭环零点 D. 开环零点 题目34 控制系统闭环传递函数的分子多项式的根称为该系统的 。
选择一项:
A. 开环极点 B. 闭环极点 C. 闭环零点 D. 开环零点 题目35 单位斜坡函数的拉氏变换式为 。
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A. s B. 1/s C. 1/s2 D. 1 题目36 一阶系统的传递函数为则其时间常数为 。
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A. 0.5 B. 4 C. 2 D. 1 题目37 已知线性系统的输入x(t),输出y(t),传递函数G(s),则正确的关系是 。
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A. y(t)=x(t)·L-1[G(s)] B. Y(s)=G(s)·X(s) C. X(s)=Y(s)·G(s) D. Y(s)=G(s)/X(s) 题目38 控制系统的传递函数为则该系统的极点为 。
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A. 0, -2, -0.25 B. 0, -2, -2 C. 0, 0, -2, -0.25 D. 0, 0, 2, 0.25 题目39 传递函数为它包括的典型环节有 。
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A. 积分环节和比例环节 B. 惯性环节 C. 惯性环节和比例环节 D. 微分环节 题目40 传递函数可用来作为 系统的数学模型。
选择一项:
A. 线性系统 B. 非线性系统和线性系统 C. 非线性系统 D. 所有类型的系统 形考任务2 一、判断题(共20道,每道2分) 题目1 时间常数T越大,一阶系统跟踪单位斜坡输入信号的稳态误差越小。
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对 错 题目2 二阶系统在欠阻尼下阶跃响应表现为等幅振荡的形式。
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对 错 题目3 一阶系统的动态响应速度和其时间常数有关。
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对 错 题目4 两个二阶系统若具有相同的阻尼比,则这两个系统具有大致相同的超调量。
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对 错 题目5 两个二阶系统若具有相同的阻尼比,则这两个系统具有大致相同的超调量。
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对 错 题目6 两个二阶系统具有相同的超调量,则这两个系统具有相同的无阻尼自振荡角频率 选择一项:
对 错 题目7 一阶系统的时间常数越小,其动态响应速度越快。
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对 错 题目8 二阶系统的调节时间和阻尼比及无阻尼自振荡角频率的乘积成反比。
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对 错 题目9 二阶系统的阻尼比越小,振荡性越强。
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对 错 题目10 对于Ⅰ型系统,在单位阶跃输入信号下的稳态误差为零。
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对 错 题目11 劳斯表第一列系数符号改变了两次,说明该系统有两个根在右半s平面。
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对 错 题目12 如果在扰动作用下系统偏离了原来的平衡状态,当扰动消失后,系统能够以足够的准确度恢复到原来的平衡状态,则系统是稳定的。否则,系统不稳定。
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对 错 题目13 在计算中劳斯表的某一行各元素均为零,说明特征方程有关于原点对称的根。
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对 错 题目14 0型系统在阶跃输入作用下存在稳态误差,常称有差系统。
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对 错 题目15 0型系统不能跟踪斜坡输入,Ⅰ型系统可跟踪,但存在误差,Ⅱ型及以上在斜坡输入下的稳态误差为零。
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对 错 题目16 二阶系统在零阻尼下,其极点位于S平面的右半平面。
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对 错 题目17 二阶欠阻尼系统,其阻尼比越大,系统的平稳性越好。
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对 错 题目18 系统的稳态误差和其稳定性一样,均取决于系统自身的结构与参数。
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对 错 题目19 两个二阶系统具有相同的超调量,则这两个系统具有相同的无阻尼自振荡角频率。
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对 错 题目20 当固定,增加时,二阶欠阻尼系统单位阶跃响应的调节时间将减小。
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对 错 二、选择题(共20道,每道3分) 题目21 若系统的开环传递函数为,则它的开环增益为( ) 选择一项:
a. 5 b. 10 c. 1 d. 2 题目22 二阶系统的传递函数,则该系统是( ) 选择一项:
a. 临界阻尼系统 b. 欠阻尼系统 c. 零阻尼系统 d. 过阻尼系统 题目23 若保持二阶系统的ζ不变,提高ωn,则可以( )。
选择一项:
a. 增加调整时间 b. 减少超调量 c. 减少调节时间 d. 增大超调量 题目24 设系统的特征方程为,则此系统 ()。
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a. 稳定性不确定 b. 稳定 c. 不稳定 d. 临界稳定 题目25 某一系统的速度误差为零,则该系统的开环传递函数可能是( )。
选择一项:
题目26 单位反馈系统开环传递函数为,当输入为单位斜坡函数时,其稳态误差为( )。
选择一项:
a. 0.25 b. 4 c. 0 d. 题目27 已知二阶系统单位阶跃响应曲线呈现出等幅振荡,则其阻尼比可能为( )。
选择一项:
a. 1 b. 0.6 c. 0 d. 0.707 题目28 系统的传递函数,其系统的增益和型次为 ( )。
选择一项:
a. 5,2 b. 5/4,4 c. 5,4 d. 5/4,2 题目29 若保持二阶系统的ωn不变,提高ζ,则可以( )。
选择一项:
a. 提高上升时间和峰值时间 b. 提高上升时间和调整时间 c. 减少上升时间和峰值时间 d. 减少上升时间和超调量 题目30 二阶系统的传递函数,其阻尼比ζ是( )。
选择一项:
a. 4 b. 0.5 c. 2 d. 1 题目31 二阶系统的两个极点均位于负实轴上,则其在阶跃输入下的输出响应表现为 。
选择一项:
a. 振荡发散 b. 等幅振荡 c. 单调上升并趋于稳态值 d. 衰减振荡 题目32 已知二阶系统单位阶跃响应曲线不呈现振荡特征,则其阻尼比可能为( )。
选择一项:
a. 0.707 b. 0.6 c. 0 d. 1 题目33 以下关于系统稳态误差的概念正确的是( )。
选择一项:
a. 与系统的结构和参数、输入和干扰有关 b. 它只决定于系统的结构和参数 c. 它始终为0 d. 它只决定于系统的输入和干扰 题目34 当输入为单位阶跃函数,对于开环放大系数为k的I型系统其稳态误差为() 选择一项:
a. 0 b. c. 1/(1+k) d. 0.1/k 题目35 时域分析法研究自动控制系统时最常用的典型输入信号是 ( )。
选择一项:
a. 斜坡函数 b. 抛物线函数 c. 阶跃函数 d. 脉冲函数 题目36 设控制系统的开环传递函数为,该系统为 ( )。
选择一项:
a. I型系统 b. II型系统 c. 0型系统 d. III型系统 题目37 一阶系统的时间常数T越大,则系统的输出响应达到稳态值的时间() 选择一项:
a. 不变 b. 越短 c. 越长 d. 不定 题目38 设系统的传递函数为,则系统的阻尼比为( )。
选择一项:
a. 5 b. 1 c. 1/2 d. 25 题目39 二阶系统当0<ζ<1时,如果增加ζ,则输出响应的最大超调量将 ( )。
选择一项:
a. 不变 b. 减小 c. 增加 d. 不定 题目40 某二阶系统阻尼比为0.2,则系统阶跃响应为 ( )。
选择一项:
a. 衰减振荡 b. 单调衰减 c. 发散振荡 d. 等幅振荡 形考任务3 一、判断题(共20道,每题2分) 题目1 根轨迹起始于开环极点,终止于开环零点。
选择一项:
对 错 题目2 根轨迹是连续的,对称于实轴。
选择一项:
对 错 题目3 在实轴上根轨迹分支存在的区间的右侧,开环零、极点数目的总和为偶数。
选择一项:
对 错 题目4 若在实轴上相邻开环极点之间存在根轨迹,则在此区间上一定有分离点。
选择一项:
对 错 题目5 若在实轴上相邻开环零点之间存在根轨迹,则在此区间上一定有汇合点。
选择一项:
对 错 题目6 根轨迹渐进线倾角大小为 。
选择一项:
对 错 题目7 独立的渐近线共有n-m条。
选择一项:
对 错 题目8 某单位反馈系统的开环极点个数为4,则系统根轨迹的分支数为2 。
选择一项:
对 错 题目9 单位反馈系统开环传递函数为 则其根轨迹的渐近线和实轴的夹角为。
选择一项:
对 错 题目10 单位反馈系统的开环传递函数为,则根轨迹的分支数为2,分别起始于0和-4。
选择一项:
对 错 题目11 0型系统不能跟踪斜坡输入,Ⅰ型系统可跟踪,但存在误差,Ⅱ型及以上在斜坡输入下的稳态误差为零。
选择一项:
对 错 题目12 二阶系统在零阻尼下,其极点位于S平面的右半平面。
选择一项:
对 错 题目13 二阶欠阻尼系统,其阻尼比越大,系统的平稳性越好。
选择一项:
对 错 题目14 系统的稳态误差和其稳定性一样,均取决于系统自身的结构与参数。
选择一项:
对 错 题目15 两个二阶系统具有相同的超调量,则这两个系统具有相同的无阻尼自振荡角频率。
选择一项:
对 错 题目16 系统的型别是根据系统的闭环传递函数中积分环节的个数来确定的。
选择一项:
对 错 题目17 在输入一定时,增大开环增益,可以减小稳态误差;
增加开环传递函数中的积分环节数,可以消除稳态误差。
选择一项:
对 错 题目18 最佳工程参数是以获得较小的超调量为设计目标,通常阻尼比为1. 选择一项:
对 错 题目19 系统最大超调量指的是响应的最大偏移量与终值的差与的比的百分数,即。
选择一项:
对 错 题目20 二阶系统在欠阻尼下阶跃响应表现为等幅振荡的形式。
选择一项:
对 错 二、选择题(共20道,每题3分) 题目21 若开环传递函数G(s)H(s)不存在复数极点和零点,则 ( )。
选择一项:
a. 有出射角和入射角 b. 无出射角有入射角 c. 有出射角无入射角 d. 没有出射角和入射角 题目22 n阶系统有m个开环有限零点,则有( )条根轨迹终止于S平面的无穷远处。
选择一项:
a. m–n b. n c. m d. n–m 题目23 开环传递函数为,则实轴上的根轨迹为( )。
选择一项:
a. (-3,∞) b. (-∞,-3) c. (-3,0) d. (0,∞) 题目24 系统的开环传递函数为,则实轴上的根轨迹为( )。
选择一项:
a. (-∞,-3)和(-2,0) b. (0,2)和(2,∞) c. (-3,-2)和(0,∞) d. (-∞,0)和(2,3) 题目25 根轨迹上的点应满足的幅角条件为( )。
选择一项:
a. 1 b. -1 c. ±(2k+1)π(k=0,1,2,…) d. ±(2k+1)π/2 (k=0,1,2,…) 题目26 根据( )条件是否满足来判断S平面上的某个点是否为根轨迹上的点。
选择一项:
a. 幅值条件 b. 传递函数 c. 相(幅)角条件 d. 特征方程 题目27 系统开环传递函数为,实轴上的根轨迹有( )。
选择一项:
题目28 单位反馈系统的开环传递函数为,则根轨迹的渐近线倾角为( )。
选择一项:
题目29 二阶系统当0<ζ<1时,如果增加ζ,则输出响应的最大超调量将 ( )。
选择一项:
a. 不变 b. 不定 c. 增加 d. 减小 题目30 一阶系统的阶跃响应, ( ) 。
选择一项:
a. 当时间常数T较大时有振荡 b. 当时间常数T较小时有振荡 c. 无振荡 d. 有振荡 题目31 某二阶系统阻尼比为0.2,则系统阶跃响应为 ( )。
选择一项:
a. 等幅振荡 b. 单调衰减 c. 衰减振荡 d. 发散振荡 题目32 控制系统的开环传递函数为,则该系统的型别为( )。
选择一项:
a. Ⅲ型 b. 0型 c. Ⅰ型 d. Ⅱ型 题目33 二阶控制系统的特征参数为 。
选择一项:
a. 阻尼比和无阻尼自振荡角频率 b. 阻尼比 c. 无阻尼自振荡角频率 d. 回路参数 题目34 欠阻尼的二阶系统的单位阶跃响应为 ( )。
选择一项:
a. 等幅振荡 b. 单调上升 c. 衰减振荡 d. 发散振荡 题目35 过阻尼二阶系统的两个极点位于 ( )。
选择一项:
a. 实轴的不同位置上 b. 实轴的相同位置上 c. 虚轴上 d. 复平面上 题目36 二阶系统振荡程度取决于( )。
选择一项:
a. 阻尼比 b. 无阻尼自振荡角频率 c. 阻尼比和无阻尼自振荡角频率 d. 时间常数 题目37 二阶欠阻尼系统的调节时间和( )成反比。
选择一项:
a. 无阻尼自振荡角频率 b. 阻尼比 c. 时间常数 d. 阻尼比和无阻尼自振荡角频率的乘积 题目38 一阶系统的单位阶跃响应为 。
选择一项:
a. 发散振荡 b. 衰减振荡 c. 等幅振荡 d. 单调上升并趋近于1 题目39 线性系统是稳定的,则 位于复平面的左半平面 。
选择一项:
a. 开环极点 b. 开环零点 c. 闭环极点和闭环零点 d. 闭环极点 题目40 输入相同时,系统型次越高,稳态误差 ( B ). 选择一项:
a. 越小 b. 越大 c. 不确定 d. 不变 形考任务4 一、判断题(共20道,每题2分) 题目1 频率特性是线性系统在单位阶跃函数作用下的输出响应。
选择一项:
对 错 题目2 二阶振荡环节低频渐近线为0分贝线,高频渐近线为斜率为20dB/dec的直线。
选择一项:
对 错 题目3 一阶惯性环节的转折频率为1/T。
选择一项:
对 错 题目4 积分环节的对数相频特性为+90°的直线。
选择一项:
对 错 题目5 对数幅频特性的渐近线与精确曲线相比,最大误差发生在转折频率处。
选择一项:
对 错 题目6 传递函数的极点和零点均在s平面左半平面的系统为最小相位系统。
选择一项:
对 错 题目7 控制系统的稳定性和系统自身的结构和参数及外输入有关。
选择一项:
对 错 题目8 最小相位系统的对数幅频特性和对数相频特性是一一对应的。
选择一项:
对 错 题目9 比例环节的幅相特性是平面实轴上的一个点。
选择一项:
对 错 题目10 (0.4,和填空题60互斥)比例环节稳态正弦响应的振幅是输入信号的K倍,且响应与输入同相位。
选择一项:
对 错 题目11 积分环节的幅值与ω成正比,相角恒为90°。
选择一项:
对 错 题目12 二阶振荡环节的对数幅频特性的低频段渐近线是一条-20dB/dec的直线,高频段渐近线是一条斜率为-40dB/dec的直线。
选择一项:
对 错 题目13 系统对数幅频特性的高频段具有较大的斜率,可增强系统的抗高频干扰能力。
选择一项:
对 错 题目14 时滞环节不影响系统的幅频特性,但会影响系统的相频特性。
选择一项:
对 错 题目15 二阶振荡环节的输出信号相位始终是滞后输入,滞后的极限为90°。
选择一项:
对 错 题目16 (与单选第22小题互斥,0.5)PI校正是相位超前校正。
选择一项:
对 错 题目17 (与单选第27小题互斥,0.5)PD校正是相位超前校正。
选择一项:
对 错 题目18 滞后校正主要是利用其高频衰减特性提高系统的开环增益,不能提高稳态精度以及系统的稳定性。
选择一项:
对 错 题目19 超前校正由于频带加宽,所以对高频干扰较敏感。
选择一项:
对 错 题目20 超前校正不适用于要求有快的动态响应的场合。
选择一项:
对 错 二、单项选择题(共20道,每题3分) 题目21 ω从0变化到+∞时,延迟环节频率特性极坐标图为( )。
选择一项:
a. 圆 b. 椭圆 c. 半圆 d. 双曲线 题目22 一阶微分环节,当频率时,则相频特性为( )。
选择一项:
a. -90° b. -45° c. 90° d. 45° 题目23 最小相位系统的开环增益越大,其( )。
选择一项:
a. 相位变化越小 b. 稳态误差越小 c. 稳定裕量越大 d. 振荡次数越多 题目24 一般开环频率特性的低频段表征了闭环系统的( )性能。
选择一项:
a. 动态 b. 稳态 c. 快速性 d. 稳定性 题目25 某环节的传递函数为,它的对数幅频率特性随K值增加而( )。
选择一项:
a. 右移 b. 下移 c. 上移 d. 左移 题目26 设积分环节的传递函数为,则其频率特性幅值( )。
选择一项:
题目27 在用实验法求取系统的幅频特性时,一般是通过改变输入信号的( )来求得输出信号的幅值。
选择一项:
a. 稳定裕量 b. 时间常数 c. 相位 d. 频率 题目28 II型系统对数幅频特性的低频段渐近线斜率为( )。
选择一项:
a. –40(dB/dec) b. –60(dB/dec) c. –20(dB/dec) d. 0(dB/dec) 题目29 比例环节的频率特性相位移=( )。
选择一项:
a. -90° b. 90° c. 0° d. -180° 题目30 积分环节的频率特性相位移=( ).(0.5) 选择一项:
a. 90° b. -180° c. -90° d. 0° 题目31 微分环节的频率特性相位移=( ) (0.5) 选择一项:
a. 0° b. -90° c. -180° d. 90° 题目32 一阶惯性环节在转折频率处的相位移=( )。
选择一项:
a. -180° b. 0° c. -45° d. -90° 题目33 一阶微分环节在转折频率处的相位移=( )。
选择一项:
a. +45° b. -45° c. 0° d. -180° 题目34 已知系统为最小相位系统,则一阶惯性环节的相位变化范围为( )。
选择一项:
题目35 ω从0变化到+∞时,二阶振荡环节的相位移变化范围为( )。
选择一项:
题目36 一阶惯性系统的转折频率指ω=( )。
选择一项:
a. 0.5 b. 2 c. 1 d. 0 题目37 若已知某串联校正装置的传递函数为,则它是一种( ) 选择一项:
a. 反馈校正 b. 相位滞后校正 c. 相位滞后—超前校正 d. 相位超前校正 题目38 若已知某串联校正装置的传递函数为,则它是一种( ) 选择一项:
a. 反馈校正 b. 相位超前校正 c. 相位滞后校正 d. 相位滞后—超前校正 题目39 若已知某串联校正装置的传递函数为,则它是一种( D ) 选择一项:
a. 相位超前校正 b. 相位滞后校正 c. 微分调节器 d. 积分调节器 题目40 若已知某串联校正装置的传递函数为,则它是一种( ) 选择一项:
a. 相位滞后—超前校正 b. 相位滞后校正 c. 相位超前校正 d. 反馈校正