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1、大学英语（三)拜脚啊卯 IlTVIHR C0VC4PBI大学英语（三）作业Part I. Read ing Comprehe nsionDirections:There are three passages in this part. Each passage is followed by some questions. For eachof them there are four choices marked A, B, C and D. You should decide on the best choice.Passage 1In the summer of 1978 an En gli
2、sh farmern amed Ian Steve ns was driv ing his tractor through a fieldof wheat whe n he discovered someth ing stra nge. Some of his wheat was lying flat on the ground. Theflatte ned(被压平的)wheat formed a circle about six meters across. Around this circle were foursmaller circles of flatte ned wheat. In
3、 the follow ing years more and more similar circles were foundin a field of wheat or corn. So people cannot help but ask the question: What causes the circles?At first, people suspected that the circles were a trick. To prove that the circleswere a trick, peopletried to copy them: they tried to make
4、circles exactly like the ones the farmers had found. They could nt do it. They could nten ter a field of grain without leavi ng tracks, and they could ntflatte nthe gra inwithout breaking it. The circles are apparently not a trick.Many people believe that beings from outer space are making the circl
5、es.Somethink that the beingsare trying to com muni cate with us from far away and that the circles are messages from them. Others believe that the beings have actually Ian ded on earth and that the circles are marks left by their spaceships. Several times people reported seeing strange flying object
6、s near fields where circles later appeared.Scien tists say theyre not sure what causes them. They have suggested several theories. For example,some scie ntists say that microbursts of wind created the circles. A microburst is a dow nward rushof cool air the samedownward rush of air that sometimes ca
7、uses an airplane to crash. Others scientists say that forces with in the earth cause the circles to appear. But circles ofte n appear in forms. It is hard to believe that any natural force could create those forms. And recently farmers have discovered not only circles but also other shapes such as t
8、rianglesin their fields. Could any natural force createda perfect tria ngle in a field of grain?In the summer of 1990 some scie ntists spe ntthree weeks in the part of En gla nd where many circleshave appeared. They had all the latest high-tech equipment. This equipment worth 1.8 milliondollarsrecor
9、ded nothing. But one night, as the scientists were watching a field, circles formed in thefield behind them. These circles are shown in the photograph. The scientistshad neither seen nor heardanything. (402 words)1. What causes the circles?A. Teen agers.B. Farmers. C. Flyi ng objects.D. None of the
10、above.2. The thi ng that proves that the circles were not a trick is that.A. two men said they made the circles themselvesB. farmers were maki ng the circles to attract touristsC. people cannot copy the circles without leaving marks or breaking the grainD. scie ntists suggest theories that support t
11、he idea that circles were made by n atural forces3. The circles mea n.第#页共18页0站端蹑*ICmflfFDlTVIHI CDlAnl大）A. that beings from outer space are trying to com muni cate with huma n beingsB. that beings from outer space have visited the earthC. that there do exist stra nge flying objectsD. none of the ab
12、ove4. The only thing for the scie ntists to be happy about in the summer of 1990 is possibly.A. that they discovered how the circles were madeB. that they saw the circles with the help of the latest high-tech equipme ntC. that they were able to show the circles in a photographD. none of the above5.
13、A proper title for this passage is.A. An Un solved Mystery B. Stra nge Flyi ng ObjectsC. The Power of Natural ForcesD. The Discovery of Strange CirclesPassage 2In the early days of sea travel, seamen lived entirely on salted meat and biscuits. Many of them died of scurvy （ 坏血病）,a disease of the bloo
14、d which causes swollen gums, pale white spots on the flesh and general exhaustion. On one occasion, in 1535, an English ship arrived in Newfoundland with its crew seriously ill. The mens lives were saved by Iroquois Indianswho gave them vegetable leavesto eat. Gradually it came to be realized that s
15、curvy was caused by some lack in the sailors diet and Capta in Cook, who was to discover Australia and New Zeala nd, established the fact the scurvy could be avoided by provisi on of fresh fruit for the sailors.Nowadays it is understood that a diet which contains nothing harmful may yet result in se
16、rious disease if certain important elements are missing. These elements are called vitamins. Quite a number of such substances are known and they are given letters to identify them, A, B, C, D, and so on. Different diseases are associated with deficiencies of particular vitamins. Even a slight lack of Vitamin C, for example, the vitam in
