1、大学英语四级模拟试卷 772及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed 30 minutes to write a short essay entitled aging of the population. You should write at least 150 words following the outline given below. 1我国人口老龄化现象日趋明显 2人口老龄化带来的问 题 3如何妥善解决人口老龄化问题 二、 Part II Reading Comprehension
2、(Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attached to the passage. For questions 1-7, mark： Y (for YES) if the statement agrees with the information given in the passage; N (for NO) if the statement
3、 contradicts the information given in the passage; NG (for NOT GIVEN) if the information is not given in the passage. 1 How Ice Cream Works The U.S. ice cream industry sells about a million gallons of ice cream each year, dispensing cones, gallons, pints, sundaes and other desserts through grocery s
4、tores and ice cream shops, In fact, eight percent of all the milk produced in the U.S. ends up in a frozen dairy product. Ice Cream or Frozen Dessert? Not just any frozen treat can be called ice cream. In fact, the U.S. Department of Agriculture has specific rules that define what can and cant be la
5、beled “ice cream“. To bear the “Meets USDA Ingredient Standard for Ice Cream“ stamp, it has to contain at least 10 percent milk fat, and a minimum of six percent non-fat milk solids. A gallon has to weigh at least 4.5 pounds. The range of milk fat (sometimes referred to as butter fat) used in ice cr
6、eam can go from the minimum 10 percent to a maximum of about 16 percent. Most premium ice creams use 14 percent milk fat. Higher fat content leads to better, richer taste and a creamier texture. Ice cream makers dont go higher than 16 percent because it would be costly and very high in calories. An
7、ice cream with this much milk fat would also taste so rich that people would probably eat it in smaller amounts, which would be bad news for people who sell ice cream for a living. Other frozen desserts, such as sorbets (果汁冰糕 ), low-fat ice cream, and frozen yogurt, are not technically ice cream at
8、all. Frozen custard is ice cream that has at least 1.4 percent egg yolk solids, and “soft serve“ can be any frozen milk-based dessert that has not gone through the hardening process-more on that later. In terms of specific ingredients, the recipe for ice cream is simple. But in scientific terms, its
9、 complicated stuff. Ice cream is a colloid, a type of emulsion (乳状液 ). An emulsion is a combination of two substances that dont normally mix together. Instead, one of the substances is dispersed throughout the other. In ice cream, molecules of fat are suspended in a water-sugar- ice structure along
10、with air bubbles. The presence of air means that ice cream is also technically a foam. In addition to milk fat, non-fat milk solids, sugar, and air, ice cream also contains stabilizers and emulsifiers. Stabilizers help hold the air bubble structure together and give the ice cream a better texture. A
11、lthough gelatin(凝胶 ) was originally used as a stabilizer, xanthan gum, guar gum, and other compounds are used today. Emulsifiers keep the ice cream smooth and aid the distribution of the fat molecules throughout the colloid. Egg yolks were once used, but ice cream manufacturers now tend to use other
12、 chemical compounds. These stabilizers and emulsifiers make up a very small proportion (less than one percent) of the ice cream. Making Ice Cream Whether its being made in your kitchen with a hand crank, at a local homemade ice cream shop with a stand-alone ice cream maker, or in a factory that cran
13、ks out thousands of gallons of ice cream every day, the process of making ice cream is basically the same. The only difference is the scale of the operation. First, you need ice cream mix. You can buy commercially made ice cream mix that is set to a certain milk fat content. Ice cream factories usua
14、lly make their own mix by combining milk, cream and sugar in a 3,000 gallon vat, with the proportions and mixing controlled by computers. The mix is then pasteurized ( 用巴氏法灭菌 ), or heated, to kill any harmful bacteria. If you were to make your own mix at home, you could pasteurize it by cooking it i
15、n a double boiler, or use an egg substitute or pasteurized egg product. This step is important, because otherwise people who eat your homemade ice cream could get sick due to salmonella contamination. According to the Centers for Disease Control, those most at risk include the elderly, very young ch
16、ildren, and people with compromised immune systems. The next step in production is adding flavor to the mix. There are thousands of varieties of ice cream, so just about any combination of flavors is possible. From vanilla to cinnamon, chocolate to triple chocolate fudge brownie, it all gets blended
17、 into the ice cream mix. In a factory, this step takes place in vats that hold hundreds of gallons of ice cream, while giant steel paddles do the mixing. In your kitchen, a large bowl and a food mixer will work, or even a wooden spoon and muscle power if you want some exercise. Solid chunks such as
18、pieces of fruit, chocolate chunks, marshmallows, and candy are added later. The next step is where an ice cream making machine comes into play. The mix has to be simultaneously frozen and whipped. In a factory, this happens in a giant tube surrounded by pipes. The pipes contain chemicals such as amm
19、onia that freeze the tube, but the ammonia never comes into contact with the ice cream. The ice cream mix is pumped through the tube, where it gets cold very quickly. A dasher, or blade, turns inside the tube. This whips the mixture, introducing the air bubbles that help give ice cream its structure
20、. The dasher also serapes the sides of the tube, clearing off ice crystals that form there. This prevents large ice crystals from mining the flavor and texture of the ice cream. All the elements of this process are carefully monitored and controlled by computers. Most homemade ice cream shops use a
21、batch freezer for this step, where the same process happens on a smaller scale. This step can be accomplished at home with a rock salt/ice mixture for freezing and a hand or electric cranked dasher to mix and scrape off the ice crystals. Once the ice cream has come out of the ice cream maker, the pr
22、ocess isnt finished. At this point, the mixture is frozen, but still soft Large chunks of candy and other goodies are now added. Then the ice cream is placed into containers. Factory machines pour it straight into cartons or buckets, or it can be extruded ( 挤压出 ) into shapes that have wooden sticks
23、placed into them for individual treats. Now the ice cream needs to be reduced to a very low temperature, zero degrees Fahrenheit or below. Factories make it even colder since they need the ice cream to stay frozen while it is packaged and loaded onto trucks. It needs to be very cold to freeze the ic
24、e cream quickly and prevent the formation of large ice crystals. This process is known as hardening. “Soft-serve“ is often simply ice cream that has not gone through this process. Well learn about the ice cream industry in the next section. Ice Cream Industry In 1999, retail sales of ice cream in th
25、e U.S., the worldwide leader in ice cream production, topped 4 billion. In 2002, more than 20 billion was spent on frozen desserts. The leading states in ice cream consumption are California, Indiana, Pennsylvania, Texas and New York. Americans ate an average of 21.5 quarts of ice cream per person i
26、n 2004. With that much money to be made, the ice cream industry can be secretive and underhanded (秘密的 ). Deborah Hanny, owner of Sweet Jennys Ice Cream in Williamsville, NY, protects her recipes carefully. Her shop has been photographed by men in suits and she once caught someone in her upstairs off
27、ice hurriedly trying to copy down her recipes. Ice cream making secrets are seldom passed down from generation to generation these days. So where do people in the ice cream industry learn their craft? At ice cream school. Pennsylvania State University offers a week-long “Ice Cream Short Course“ inte
28、nded for industry professionals. The course teaches the science and technology used to make ice cream. They also offer Ice Cream 101 for ice cream hobbyists who just want to learn more about their favorite frozen treat. The University of Guelph, Ontarios Dairy Science and Technology school, also has
29、 a long history of teaching ice cream science. 2 Eight percent of all the milk produced in the U.S. ends up in a frozen dairy product. （ A） Y （ B） N （ C） NG 3 Any frozen treat can be called ice cream. （ A） Y （ B） N （ C） NG 4 In addition to milk fat, non-fat milk solids, sugar, and air, ice cream als
30、o contains stabilizers and emulsifiers. （ A） Y （ B） N （ C） NG 5 The process of making ice cream at home is different from that in a factory. （ A） Y （ B） N （ C） NG 6 Once the ice cream has come out of the ice cream maker, the process is finished. （ A） Y （ B） N （ C） NG 7 Ice cream making secrets are p
31、assed down from generation to generation these days. （ A） Y （ B） N （ C） NG 8 Many universities in U.S.A. offer courses of ice cream science. （ A） Y （ B） N （ C） NG 9 The range of milk fat used in ice cream can go _. 10 In 1999, retail sakes of ice cream in the U.S. topped _. 11 With that much money t
32、o be made, the ice cream industry can be _. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only once.
33、 After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer. （ A） They dont like to go swimming. （ B） They cannot swim in the lake. （ C） They wont go swimming in the lake today. （ D） They plan to swim in the l
34、ake tomorrow. （ A） They am going toward the lake. （ B） They have made decision to stay outdoors. （ C） They have taken a new trail. （ D） They plan to camp beside the lake. （ A） She wanted to show people her crafts. （ B） She has seen the exhibition. （ C） Shed rather go hack home. （ D） Shes sorry to ha
35、ve missed the exhibit. （ A） She likes climate here. （ B） She seldom cooked food for the man. （ C） She hopes the weather can be hotter. （ D） She knows shell like the food. （ A） He had a doctor examine his injury. （ B） He will go to practice tomorrow. （ C） He didnt call the woman yesterday. （ D） He as
36、ked a friend to take him to clinic. （ A） That they be on time to turn in the paper. （ B） That they finish their assignment early. （ C） That they be watchful of their words. （ D） That they stay late to finish the paper. （ A） He knows someone who lost there jobs. （ B） Greg only got the job because of
37、his uncle. （ C） Greg and his uncle work as accountants. （ D） He doesnt know the mans uncle. （ A） Hell go to the party alone. （ B） He has changed his plans. （ C） He will take the woman to the party. （ D） He wont be late for the party. （ A） A newspaper. （ B） The government. （ C） A construction firm （
38、D） A private company, （ A） Because her husband likes her to work for a firm. （ B） Because she prefers working for the government. （ C） Because self-employed work is very demanding. （ D） Because self-employed work is sometimes insecure. （ A） Because she needs money to start a family. （ B） Because she
39、 is not qualified with the government. （ C） Because she has preferences in private company. （ D） Because its more likely to get promotion in private company. （ A） A tale related to bamboo. （ B） Different kinds of bamboo. （ C） Bamboo artifacts in Japanese culture. （ D） The use of bamboo in Asian coun
40、tries. Section B Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D.
41、（ A） A real change in body chemistry. （ B） Importance of much sunlight. （ C） Effects of less sunlight in winter. （ D） Relationship between sunlight and health. （ A） It may make people dizzy. （ B） It may burn ones clothes. （ C） It may cause skin cancer or damage eyes. （ D） It may do great damage to c
42、rops. （ A） Because it can treat emotional problems and stone kinds of cancer. （ B） Because it can make stores brighter. （ C） Because it can make skin tender. （ D） Because people want to stay away from dark places. （ A） It is entertaining. （ B） It is a costly hobby. （ C） It takes lots of time. （ D） I
43、t requires training. （ A） They can harm nearby plants. （ B） They may catch some disease. （ C） They fight each other for food. （ D） They may pollute the environment. （ A） Place the food on warmer spots. （ B） Use prepared feed mixtures only. （ C） Avoid using any contaminated food. （ D） Continue the fe
44、eding till it gets warm. （ A） Fall （ B） Rise （ C） V-shape （ D） Zigzag （ A） To embrace changes of thought （ B） To adapt to the disintegrated family life （ C） To return to the practice in the 60s and 70s （ D） To create stability in their lives （ A） They feared the complicated procedures. （ B） They wan
45、ted to go against the trend. （ C） They were afraid of losing face. （ D） They were willing to stay together. （ A） been shifted around the country （ B） had difficulty being promoted （ C） enjoyed a happier life （ D） tasted little bitterness of disgrace Section C Directions: In this section, you will he
46、ar a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 t
47、o 46 you are required to fill in the missing information. For these blanks, you can either use the exact words you have just heard or write down the 33 To be a good teacher, you need some of the【 B1】 _of a good actor. You must be able to hold the attention and interest of your【 B2】 _; you must be a
48、clear speaker, with a good, strong,【 B3】 _voice; and you must be able to act what you are teaching, to make its meaning【 B4】 _comprehensible. Watch a good teacher, and you will see that he does not just sit【 B5】 _before his class: he stands the whole time he is teaching; he walks about, using his ar
49、ms, hands and fingers to help him in his【 B6】 _. Listen to him, and you will hear the【 B7】_, the quality and the musical note of his voice always changing according to what he is talking about. The fact that a good teacher has some of the qualities of a good actor doesn t mean that he will【 B8】 _be able to act well on the stage.【 B9】 _. The actor has to speak words which he has learnt by heart; he has to repeat exactly the same words each time he plays a certain
