1、大学英语四级分类模拟题 503及答案解析(总分：207.50，做题时间：90 分钟)一、Part Writing(总题数：1，分数：20.00)1.For this part, you are allowed 30 minutes to write a short essay about a friend that helped you most. You should state the reasons and write at least 120 words but no more than 180 words. （分数：20.00）_二、Part Reading Compr(总题数：0，
2、分数：0.00)四、Passage One(总题数：1，分数：71.00)Today“s lecture is about two powerful natural forces, one destructive, yet the other productive. Tornado (龙卷风) is a typical example of destructive forces in nature. Forces other than damaging winds are also at work inside tornadoes. Sometimes as twisting, screami
3、ng wind passes over house, the walls and the ceiling burst apart as if a bomb had gone off inside. This explosion is caused by the low air pressure at the center of a tornado. The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house the air pressure is
4、normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and outside pressure may not seem like much. But suppose a tornado passes over a small building that measures 20 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from
5、the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unbalanced pressure of 57,600 pounds. The pressure on the four walls adds up to 172,800 pounds. If windows are open in the building, some of the inside air will rush out through them. This will b
6、alance the pressure inside and outside the building. But if the windows are shut tightly, the enormous inside pressure may cause the building to burst. Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their
7、 property, which may cause far worse damage later. For the same reason, tornado cellars must have an air opening. Otherwise, the cellar door might be blown out when a tornado passes over it. Even more amazing is the strong force of plants in water evaporation (蒸发). The task of carrying 40 gallons of
8、 water up almost 60 feetto an apartment on the sixth floor, for instanceis an undeniably heavy task. And yet it is no more than a full-grown tree does on any warm day. For 400 trees 75 to 90 feet high, the leaves evaporate an average of 20 tons of water on a single dayequivalent to the capacity of a
9、 larger tanker truck. Before this water evaporates it is lifted an average of 80 feet through trunks and branches. Anyone thinks this a trifle would do well to work out how many bucks it would mean, to which floor. Quite an achievement. The surprising thing is that the plants themselves need supply
10、no energy to do this. Everything happens automatically. The evaporation from the leaf surface causes a constant compensatory suction (吸) of water. This suction communicates itself through branch and trunk down into roots. The suction force caused by evaporation from the tiny openings of the leaves i
11、s tremendously strong. When, on a dry summer“s day, the surrounding atmosphere has a relative humidity (湿度) of 45 percent, the evaporation suction corresponds to the pull exerted on a rope 3 mm in diameter by a 154-pound man suspended from it! Thus evaporation actually draws the water from the leave
12、s by force, and pulls more water up to replace it. The driving force is the sun and plants make direct use of its energy for water transport. Once again, we see the powerful, unlimited energy in nature.（分数：71.00）(1).According to the passage, tornadoes can destroy buildings because the _.（分数：14.20）A.
13、force of tornado increases the air pressure in a buildingB.air pressure at the center of a tornado is as strong as over 172,000 poundsC.weight of a tornado can crush a building“s roof when it passes overheadD.air pressure inside a tornado is less than air pressure inside a building(2).The pressures
14、on a building during tornado can be relieved by _.（分数：14.20）A.closing the cellarB.opening the windowC.using a fan for air circulationD.strengthening the roof and walls(3).People often close their windows to prevent damage caused by _.（分数：14.20）A.tornadoesB.thunderstormsC.bursting structuresD.uproote
15、d trees(4).The underlined word “trifle“ in Paragraph 5 is closest in meaning to _.（分数：14.20）A.unimportant thingB.hard jobC.great eventD.incredible thing(5).Which of the following is NOT given as a comparison to the force of plants in evaporation?（分数：14.20）A.Carrying water up to the sixth floor in ap
16、artment.B.The pulling force exerted on a rope by a strong man hanging from it.C.Lifting water up to 80 feet high in plants before evaporation.D.The transporting capacity of a big tanker lorry.五、Passage Two(总题数：1，分数：10.00)There seems never to have been a civilization without toys, but when and how th
17、ey developed is unknown. They probably came about just to give children something to do. In the ancient world, as is today, most boys played with some kinds of toys and most girls with another. In societies where social roles are rigidly determined, boys pattern their play after the activities of th
18、eir fathers and girls after the tasks of their mothers. This is true because boys and girls are being prepared, even in play, to step into the roles and responsibilities of the adult world. What is remarkable about the history of toys is not so much how they changed over the centuries but how much t
19、hey have remained the same. The changes have been mostly in terms of craftsmanship, mechanics, and technology. It is the universality of toys with regard to their development in all parts of the world and their persistence to the present that is amazing. In Egypt, the Americas, China, Japan and amon
20、g the Arctic (北极的) peoples, generally the same kinds of toys appeared. Variations depended on local customs and ways of life because toys imitate their surroundings. Nearly every civilization had dolls, little weapons, toy soldiers, tiny animals and vehicles. Because toys can be generally regarded a
21、s a kind of art form, they have not been subject to technological leaps that characterize inventions for adult use. The progress from the wheel to the oxcart to the automobile is a direct line of ascent (进步). The progress from a rattle (拨浪鼓) used by a baby in 3000 BC to one used by an infant today,
22、however, is not characterized by inventiveness. Each rattle is the product of the artistic tastes of the times and subject to the limitations of available materials.（分数：10.00）(1).The reason why the toys most boys play with are different from those that girls play with is that _.（分数：2.00）A.their soci
23、al roles are rigidly determinedB.most boys would like to follow their fathers“ professionsC.boys like to play with their fathers while girls with their mothersD.they like challenging activities(2).One aspect of “the universality of toys“ lies in the fact that _.（分数：2.00）A.technological advances have
24、 greatly improved the durability of toysB.the improvement of craftsmanship in making toys depends on the efforts of universitiesC.the exploration of the universe has led to the creation of new kinds of toysD.the basic characteristics of toys are the same the world over(3).Which of the following is t
25、he author“s view on the historical development of toys?（分数：2.00）A.The craftsmanship in toy-making has remained essentially unchanged.B.Toys have remained basically the same all through the centuries.C.The toy industry has witnessed great leaps in technology in recent years.D.Toys are playing an incr
26、easingly important role in shaping a child“s character.(4).Regarded as a kind of art form, toys _.（分数：2.00）A.follow a direct line of ascentB.also appeal greatly to adultsC.are not characterized by technological progressD.reflect the pace of social progress(5).The author uses the example of a rattle
27、to show that _.（分数：2.00）A.in toy-making there is a continuity in the use of materialsB.even the simplest toys can reflect the progress of technologyC.it often takes a long time to introduce new technology into toy-makingD.even a simple toy can mirror the artistic tastes of the time六、Part Translation
28、(总题数：1，分数：106.50)2.在中国，裸婚，即无房产结婚，正被越来越多的年轻人认可。但随着年龄的增长，他们的态度会改变。结婚前通常要先办理房贷。人们普遍认为，一个男性及其家庭若无力购房，他将很难找到新娘。根据最近一份对中国沿海城市年轻人的调查，三分之一的女性择偶时会考虑对方的购房能力。就算女性自己不考虑该条件，她的家人和朋友，更不用说中国房产商，都不会让她忘记这点。 （分数：106.50）_大学英语四级分类模拟题 503答案解析(总分：207.50，做题时间：90 分钟)一、Part Writing(总题数：1，分数：20.00)1.For this part, you are all
29、owed 30 minutes to write a short essay about a friend that helped you most. You should state the reasons and write at least 120 words but no more than 180 words. （分数：20.00）_正确答案：()解析：参考范文 Without a doubt, Marco is the one who has helped me most in college. As my partner in the community, he encourag
30、es others in a positive way and sticks to everything all the time. It was Marco who kept teaching me how to overcome difficulties when facing challenges. I still remember that I felt so frustrated at the loss of a key sponsorship that I even wanted to quit the community. However, Marco reminded me,
31、“Victory and defeat are both common in battle. Never give up and keep trying. If you hesitate, your opportunity to succeed will go away.“ With his help, I finally regained my confidence and secured a sponsorship for my community after several strenuous attempts. Thanks to Marco, I have realized the
32、importance of courage and confidence, which are essential for a successful life. Whenever I feel upset, his voice will echo in my ear: Never give up and keep trying.二、Part Reading Compr(总题数：0，分数：0.00)四、Passage One(总题数：1，分数：71.00)Today“s lecture is about two powerful natural forces, one destructive,
33、yet the other productive. Tornado (龙卷风) is a typical example of destructive forces in nature. Forces other than damaging winds are also at work inside tornadoes. Sometimes as twisting, screaming wind passes over house, the walls and the ceiling burst apart as if a bomb had gone off inside. This expl
34、osion is caused by the low air pressure at the center of a tornado. The pressure at the center of a tornado is usually 13 pounds per square inch. However, inside the house the air pressure is normal, about 15 pounds per square inch. The difference of 2 pounds per square inch between the inside and o
35、utside pressure may not seem like much. But suppose a tornado passes over a small building that measures 20 by 10 feet. On each square inch of the building, there is 2 pounds of pressure from the inside that is not balanced by air pressure outside the building. On the ceiling, that adds up to an unb
36、alanced pressure of 57,600 pounds. The pressure on the four walls adds up to 172,800 pounds. If windows are open in the building, some of the inside air will rush out through them. This will balance the pressure inside and outside the building. But if the windows are shut tightly, the enormous insid
37、e pressure may cause the building to burst. Unfortunately, heavy rain and hail often occur in thunderstorms that later produce tornadoes. So people frequently shut all windows to protect their property, which may cause far worse damage later. For the same reason, tornado cellars must have an air ope
38、ning. Otherwise, the cellar door might be blown out when a tornado passes over it. Even more amazing is the strong force of plants in water evaporation (蒸发). The task of carrying 40 gallons of water up almost 60 feetto an apartment on the sixth floor, for instanceis an undeniably heavy task. And yet
39、 it is no more than a full-grown tree does on any warm day. For 400 trees 75 to 90 feet high, the leaves evaporate an average of 20 tons of water on a single dayequivalent to the capacity of a larger tanker truck. Before this water evaporates it is lifted an average of 80 feet through trunks and bra
40、nches. Anyone thinks this a trifle would do well to work out how many bucks it would mean, to which floor. Quite an achievement. The surprising thing is that the plants themselves need supply no energy to do this. Everything happens automatically. The evaporation from the leaf surface causes a const
41、ant compensatory suction (吸) of water. This suction communicates itself through branch and trunk down into roots. The suction force caused by evaporation from the tiny openings of the leaves is tremendously strong. When, on a dry summer“s day, the surrounding atmosphere has a relative humidity (湿度)
42、of 45 percent, the evaporation suction corresponds to the pull exerted on a rope 3 mm in diameter by a 154-pound man suspended from it! Thus evaporation actually draws the water from the leaves by force, and pulls more water up to replace it. The driving force is the sun and plants make direct use o
43、f its energy for water transport. Once again, we see the powerful, unlimited energy in nature.（分数：71.00）(1).According to the passage, tornadoes can destroy buildings because the _.（分数：14.20）A.force of tornado increases the air pressure in a buildingB.air pressure at the center of a tornado is as str
44、ong as over 172,000 poundsC.weight of a tornado can crush a building“s roof when it passes overheadD.air pressure inside a tornado is less than air pressure inside a building 解析：细节推断题。本文第三段提到，由于室内正常气压与龙卷风中心低气压的差异，平均每平方英寸有2磅的向外压力不能被向内的压力抵消。根据第四段第三句“But if the windows are shut tightly, the enormous in
45、side pressure may cause the building to burst.”可推知，紧闭的窗户使内外空气不流通，室内压力积聚，最后巨大的室内压力导致房屋爆裂。(2).The pressures on a building during tornado can be relieved by _.（分数：14.20）A.closing the cellarB.opening the window C.using a fan for air circulationD.strengthening the roof and walls解析：细节题。参见第四段第一、二句“If the w
46、indows are open.outside the building.”(若打开楼房窗户，室内的一些空气可以流出。这将使楼房内外压力得以平衡。)(3).People often close their windows to prevent damage caused by _.（分数：14.20）A.tornadoesB.thunderstorms C.bursting structuresD.uprooted trees解析：细节题。参见第四段第四、五句“Unfortunately, heavy rain and hail often occur in thunderstorms.may
47、 cause far worse damage later.”(不幸的是，雷暴雨往往先带来大雨与冰雹，随后便产生龙卷风。所以人们经常要关闭所有门窗以保护室内财产。)(4).The underlined word “trifle“ in Paragraph 5 is closest in meaning to _.（分数：14.20）A.unimportant thing B.hard jobC.great eventD.incredible thing解析：生词猜测题。参见最后一段“Before this water evaporates it is lifted an average of
48、80 feet through trunks and branches. Anyone thinks this a trifle would do well to work out how many bucks it would mean, to which floor. Quite a considerable achievement.”(这 20顿水分在蒸发之前先要沿树干与树枝平均每日上升 80英尺。如果有人认为这只是小事一桩，试想一下 20吨的水上升 80英尺意味着要提多少桶水爬多少层楼。)(5).Which of the following is NOT given as a comparison to the force of plants in evaporation?（分数：14.20）A.Carrying water up to the sixth floor in apartment.B.The pulling force exerted on a rope by a strong man hanging from it.C.Lifting water up to 80 feet high in plants before evaporation. D.The tr
