大学四级-28及答案解析.doc

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1、大学四级-28 及答案解析(总分：693.00，做题时间：90 分钟)一、BPart Writing(总题数：1，分数：106.00)1.1. 有些人愿意和父母居住在一起 2. 有些人想自己独立居住 3. 我的看法 BStyles of Living/B（分数：106.00）_二、BPart Reading (总题数：1，分数：70.00)BHow Ice Cream Works/BThe U.S. ice cream industry sells about a million gallons of ice cream each year, dispensing cones, gallons

2、, pints, sundaes and other desserts through grocery stores and ice cream shops, In fact, eight percent of all the milk produced in the U.S. ends up in a frozen dairy product.BIce Cream or Frozen Dessert?/BNot just any frozen treat can be called ice cream. In fact, the U.S. Department of Agriculture

3、has specific rules that define what can and cant be labeled “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

4、 (sometimes referred to as butter fat) used in ice cream 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 beca

5、use it would be costly and very high in calories. An 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, a

6、nd frozen yogurt, are not technically ice cream at 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

7、 ice cream is simple. But in scientific terms, its 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

8、 suspended in a water-sugar- ice structure along 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 tog

9、ether and give the ice cream a better texture. Although 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, bu

10、t ice cream manufacturers now tend to use other chemical compounds. These stabilizers and emulsifiers make up a very small proportion (less than one percent) of the ice cream.BMaking Ice Cream/BWhether its being made in your kitchen with a hand crank, at a local homemade ice cream shop with a stand-

11、alone ice cream maker, or in a factory that cranks 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 cer

12、tain milk fat content. Ice cream factories usually 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 a

13、t home, you could pasteurize it by cooking it in 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

14、most at risk include the elderly, very young children, 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 tripl

15、e chocolate fudge brownie, it all gets blended 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

16、 you want some exercise. Solid chunks such as 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 p

17、ipes. The pipes contain chemicals such as ammonia 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 b

18、ubbles that help give ice cream its structure. 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 co

19、mputers. Most homemade ice cream shops use a 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

20、has come out of the ice cream maker, the process 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 (

21、 挤压出 ) into shapes that have wooden sticks 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.

22、 It needs to be very cold to freeze the ice 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.BIce Cream Industry

23、/BIn 1999, retail sales of ice cream in the 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 averag

24、e of 21.5 quarts of ice cream per person in 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

25、 once caught someone in her upstairs office 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

26、week-long “Ice Cream Short Course“ intended 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

27、Science and Technology school, also has a long history of teaching ice cream science.（分数：70.00）(1).Eight percent of all the milk produced in the U.S. ends up in a frozen dairy product.（分数：7.00）填空项 1:_(2).Any frozen treat can be called ice cream.（分数：7.00）填空项 1:_(3).In addition to milk fat, non-fat mi

28、lk solids, sugar, and air, ice cream also contains stabilizers and emulsifiers.（分数：7.00）填空项 1:_(4).The process of making ice cream at home is different from that in a factory.（分数：7.00）填空项 1:_(5).Once the ice cream has come out of the ice cream maker, the process is finished.（分数：7.00）填空项 1:_(6).Ice c

29、ream making secrets are passed down from generation to generation these days.（分数：7.00）填空项 1:_(7).Many universities in U.S.A. offer courses of ice cream science.（分数：7.00）填空项 1:_(8).The range of milk fat used in ice cream can go _.（分数：7.00）填空项 1:_(9).In 1999, retail sakes of ice cream in the U.S. topp

30、ed _.（分数：7.00）填空项 1:_(10).With that much money to be made, the ice cream industry can be _.（分数：7.00）填空项 1:_三、BPart Listenin(总题数：3，分数：105.00)Questions 11 to 18 are based on the conversation you have just heard.（分数：56.00）A.The class thought the demonstration was too complex.B.Too many students showed

31、up.C.The professor didnt show up.D.The professor cancelled it.A.Because nine is an odd number.B.Because the elevator is too old.C.Because the elevator got stock.D.Because there are too many people in the elevator.A.The rain has stopped.B.She is looking for her clothes.C.She wants to soak her clothes

32、.D.Its raining heavily.A.She goes home for lunch.B.She gets interested in what she is reading.C.She spends her time shopping.D.She doesnt wake up in time.A.To buy some potatoes.B.To have some potatoes.C.To pass him some potatoes.D.To help him cook some potatoes.A.It involved a few lunches.B.There we

33、re three lunches.C.There were free lunches.D.There were more than free lunches.A.He decided to continue his project.B.He was unable to get sufficient money.C.Lack of land prevented his success.D.He was successful with his project.A.Painting the room white.B.Waiting the man to decide.C.Buying white f

34、urniture.D.Asking Mr. White for advice.Questions 19 to 22 are based on the conversation you have just heard.（分数：28.00）A.In the student recreation center.B.In the university bookstore.C.In the campus dining hall.D.In a classroom.A.Studying.B.Playing cards.C.Preparing snacks.D.Learning how to play bri

35、dge.A.Miss her card game.B.Take too heavy a work load next semester.C.Stay up too late.D.Neglect her studies to play bridge.A.He already knows how to play.B.He doesnt have a partner.C.He doesnt like to play games.D.He doesnt have enough free time.BQuestions 23 to 25 are based on the conversation you

36、 have just heard./B（分数：21.00）A.The effect of the atmosphere on rainfall.B.How water originated on earth.C.How conditions on earth support life.D.A new estimate of the age of earth.A.The surface of the ocean is expanding.B.The surface of earth contains tons of cosmic dust.C.Volcanic activity is incre

37、asing.D.Thousands of comets are colliding with earths atmosphere.A.They are found under the oceans.B.Their emissions created earths atmosphere.C.They were most active when earth was first formed.D.Their fumes are mostly water in the state of a gas.四、BSection B/B(总题数：3，分数：70.00)BPassage OneQuestions

38、26 to 28 are based on the passage you have just heard./B（分数：21.00）A.He was trained as an electronics engineer.B.He was trained as a communication engineer.C.He was trained as a mechanical engineer.D.He was trained as a nuclear engineer.A.Fishing and hunting.B.Nuclear science.C.He began to show great

39、 interest in natural beauty.D.Amateur radio.A.An old friend of his.B.His younger brother.C.His elder brother.D.His younger son.BPassage TwoQuestions 29 to 31 are based on the passage you have just heard./B（分数：21.00）A.The Bachelors degree.B.The Masters degree.C.The Associate degree.D.The Doctors degr

40、ee.A.A technical associate degree.B.A bachelors degree.C.A degree which is designed for transfer.D.The last degree one can ever hope to attain.A.120 quarter hours.B.120 credit hours.C.95 quarter hours.D.72 credit hours.BPassage ThreeQuestions 32 to 35 are based on the passage you have just heard./B（

41、分数：28.00）A.In 1848.B.In 1884.C.In 1846.D.In 1849.A.8,000 people.B.80,000 people.C.10,000 people.D.100,000 people.A.From the western United States.B.From only the east coast of the American Continent.C.From all parts of the country.D.From San Francisco Bay.A.Because many settlements were abandoned.B.

42、Because private gold could not be protected by law.C.Because there were many gold-hungry sailors.D.Because everybody raced for California.五、BSection C/B(总题数：1，分数：77.00)Mark Twain, who wrote the story were going to read, traveled quite a lot often because circumstamces, usuallyU (36) /U circumstances

43、, forced him to. He was born in Florida, Missouri in 1835 and moved to Hannibal, Missouri with his family when he was about 4 years old. Most people think he was born in Hannibal but that isnt true. After his father died when he was about 12, Twain worked in Hannibal for a while and then left, so he

44、 couldU (37) /Umore money. He worked for a while as a typesetter on U(38) /U newspapers and then got a job as a river U(39) /U on the Mississippi. Twain loved this job and many of his books show it. The river job didnt last, however, because of the U(40) /U of the Civil War. Twain, was in the U(41)

45、/U Army for just 2 weeks and then he and his whole U(42) /U went west to get away from the war and the army. In Nevada and California Twain U(43) /U for silver and gold without much luck, but did succeed as a writer. U(44) /U. U(45) /U. U(46) /U.（分数：77.00）(1).（分数：7.00）填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项

46、 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_六、BPart Reading (总题数：1，分数：90.00)Perhaps like most Americans you have some extra pounds toU (47) /U. You may even have tried a fad diet or two, but found yourself right back where you started. The key to weight loss is regularU (48) /Uactivity. And surpri

47、singly, you dont have to give up eating or make the gym your second home to see long-term,U (49) /Ueffects.Your body needs a certain amount of energy to maintain basicU (50) /Usuch as breathing, blood circulation and digestion. The energy required to keep your organs functioning is referred to as the resting or basal metabolic rate.Any time you are active,U (51) /Uenergy is required. It is obtained from glycogen and fat stored in the blood, liver, and muscles. The k