大学英语四级模拟试题(4)

　　CLOZE
　　American teenagers have always worked for extra pocket money. More than their predecessors, today's adolescents are __51__ to work long 51. A） about B） fond hours during the week for hundreds of C） likely D） possible dollars each month. They spend the money __52__ themselves rather than 52. A） by B） on C） in D） for __53__ it to their families. In a 1987 53. A） contributing B） contribute C） paying D） pay __54__ of 16,000 high school seniors 54. A） view B） inspection C） observation D） survey nationwide, it was __55__ that eighty 55. A） suggested B） found percent of students who work spend C） recommended D） advised their earnings on their own needs, __56__ clothing, stereo equipment, 56. A） for example B） such as C） that is to say D） in other words records and __57__. __58__ five 57. A） going to the movie B） going to movies C） movies D） the movie percent said they contributed most 58. A） Other B） Only of their income, which often exceeded C） Additional D） Further？？200 a month, to help pay family living __59__ . 59. A） expenses B） money The benefits of this work-and- C） values D） charges spend ethic are being __60__ debated. 60. A） furiously B） heatedly C） thoroughly D） entirely __61__ experts, and many parents, 61. A） No B） All C） Any D） Some __62__ that year-round part-time 62. A） insist B） demand employment increases youngsters' sense C） suggest D） require of worth, teaches them financial__63__ 63. A） accounts B） ability C） responsibility D） well-being and reduces tension —— and thus __64__ 64. A） crash B） conflict—— within the family. C） battle D） struggle Others, __65__, argue that working 65. A） furthermore B） therefore teenagers are inappropriately separat- C） however D） besides ed, physically and financially, __66__ 66. A） in B） with C） from D） by their families, which __67__ parental 67. A） weakens B） loses authority. C） reduces D） destroys Teenagers' schoolwork can also __68__. “When youngsters work for 68. A） be suffered B） suffer C） be suffered from D） suffer from luxuries, they are buying __69__ 69. A） destruction B） separation from education,” said a program C） affection D） distraction director for the U.S. Department of Education. Working teenagers them- selves say they have __70__ time to 70. A） more B） less spend with friends and family. C） reduced D） sufficient
　　READING COMPREHENSION
　　Questions 71 to 75 are based on the following passage：
　　It was very late before Guglielmo followed his brother up to bed, foran extraordinary idea had come to him. If a spark could cause ether wavesto travel to another machine across a room and make that machine spark,why couldn't a bigger spark make waves travel a longer distance and causeanother spark, say, a mile away？ And, by using long and short sparks, whycouldn't this be used to send messages by Morse Code？ Indeed, why shouldn'tmessages be sent this way over great distances, using the ether instead ofwires？
　　The elder man found his young brother poor company during the rest ofthat holiday, for Guglielmo was so interested in his idea that he couldnot take his thoughts off it.
　　At last they arrived home at their father's mansion outside Bjologna,and young Marconi hurried to his laboratory to start his experiments.Assisted by his brother Alfonso, who, although nine years his senior, was not ashamed to work under this brilliant young scientist, he struggled formonths testing his idea. At last, to their joy, they got the instrument atthe other end of the room to give its answering spark.
　　Marconi now decided to show his father that there really was somethingin this idea of his, for Signor Marconi, who had made a large fortune inbusiness, had not a great deal of faith in his youngest son's science.
　　At last the apparatus was ready, and Guglielmo invited his father andmother to come to the laboratory.
　　Signor Marconi entered, his good-humoured face beaming.“What is thisnew toy you have made, my boy？”he asked.
　　“Listen.” the young inventor said, and he pressed a switch. Faintly, in the lower part of the big house, an electric bell rang.“Well？”his father inquired.“There are no wires running to that bell. Don't you see what it means.Father？ Messages can be sent through space without wires to carry them.”
　　But Signor Marconi was not convinced.“Let me take one of your machinesdown to the lawn. Then, if you can send me a signal, I'll believe you.”he said.
　　Marconi took him at his word. A little later he was back in the lab, hishand on the morse key. Through the window he could see his father at thereceiver. The young man's heart thumped as he tapped ？- the test signal, S,which telegraphists use. He could tell by the expression on his father'sface that the message had got through.
　　That evening Signora Marconi talked to her husband and on the followingday Guglielmo was overjoyed to receive from his father 5,000 lire —— about？？250 —— to help with his experiments.
　　71. According to Gaglielmo _______. A） any spark could send ether waves to wherever it wanted B） ether waves could be used to operate machines C） messages could be sent by ether instead of wires D） bigger sparks could travel a mile and send messages
　　72. In Guglielmo's opinion, the distance ether waves travel depends on _______. A） the force of a spark B） the size of the room C） the type of the machine D） the way the machine is operated
　　73. Guglielmo was so taken up with the idea that _______. A） he decided to put an end to his holiday B） stayed up late wondering about it C） he paid little attention to anything else D） he didn't want to stay with his brother
　　74. His father didn't see the point of his invention till _______. A） he heard the bell ring B） he saw the apparatus C） he listened to his son's explanation D） he received the signal himself with the machine
　　75. What is implied in the passage？
　　A） Guglielmo was better than his brother in science. B） His father was so fascinated by his invention that he proposed to join them. C） Guglielmo discovered that a spark can make other waves travel. D） Morse Code was invented by the Marconi brothers.
　　Questions 76 to 80 are based on the following passage：
　　Yellow fever is a disease of warm lands that is found mainly along theshore of the Atlantic Ocean. It was first noticed in the Americas, but maywell have come form Africa and reached the New World with or soon afterColumbus. Until about fifty years ago, yellow fever was still one of themost feared diseases in the United States, where many died in repeated out-breaks. An outbreak which was to lead to surprising developments was onethat happened in Cuba during the Spanish-American War.
　　As a result, an army group under Major Walter Reed was sent there inJune, 1900 with orders “to give special attention to questions concerningthe cause and prevention of yellow fever”。 In a daring group of experimentsusing human beings, Major Reed proved the truth of an idea advanced in 1881by a Cuban doctor, that the city type of mosquito passed on the disease.
　　The successful result of these experiments gave birth to another andstill more important idea： kill off the city type of mosquitoes and therewill be no more yellow fever. Fortunately these mosquitoes are one of theeasiest types to destroy. They are born in pools of quiet, warm water,within a short distance to people's home.
　　So to Havana came a General with orders from the United States Govern-ment to dry up these pools. He carried out his task so well that the mos-quitoes disappeared. With them went yellow fever, never to return to Havana.A few years later the same General successfully repeated this operation inPanama and in this way made possible the building of the Panama Canal. Itall seemed so simple. End the mosquitoes： end the disease. Man even beganto dream of getting rid of yellow fever from the world.
　　Meanwhile one question still remained unanswered. The city type of mosquitoes carried the fever, without doubt, but how？ After many experi-ments, a member of the United States Army Yellow Fever Commission decidedthat the disease must be carried by something too small to be seen. Ofhis own free will, this devoted scientist decided to allow himself to bebitten by an infected mosquito. Then, taking some of his infected blood,he injected it into three other members of the group who wanted to help.Two of the three got yellow fever —— and recovered. This showed that thedisease was carried by a virus （2？？？） too small to be seen through the microscopes of the day.
　　76. Yellow fever is found mainly around _______. A） the Atlantic Ocean B） Any warm ocean C） the Americas D） Any warm country
　　77. The outbreak which stirred the interest of the US Army was in _______. A） Cuba B） Spain C） Panama D） the United States
　　78. One of the reasons that yellow fever was defeated was that _______. A） some people were willing to sacrifice themselves for others B） doctors were well trained C） orders of the army had to be carried out at any cost D） public feeling was strong against the disease
　　79. When the doctors found that blood samples could carry the disease, they examined them with microscopes and saw _______. A） nothing B） virus C） germs D） different signs of disease
　　80. The building of the Panama Canal was made possible by _______. A） the success of the Spanish-American War B） the work of the United States Army C） the killing of mosquitoes nearby D） development of special drugs