| 四六级考试六级每日一练（2018/4/18） |
| 第1题：A hibernating animal needs any food all through the winter （）? A. need it B. needn't it C. does it D. doesn't it |
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| 第2题：Thereisa（）ofrawmaterialforplasticproducts.Asaresult,thepricesaregoingup. A.scarcity B.demand C.surplus D.adequacy |
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| 第3、4、5、6、7题：Television was not invented by any one person. Nor did it spring into being overnight. It evolved gradually, over a long period, from the ideas of many people -- each one building on the work of their predecessors. The process began in 1873, when it was accidentally discovered that the electrical resistance of the element selenium varied in proportion to the intensity of the light shining on it. Scientists quickly recognized that this provided a way of transforming light variations into electrical signals. Almost immediately a number of schemes were proposed for sending pictures by wire(it was, of course, before radio). One of the earliest of these schemes was patterned on the human eye. Suggested by G. R. Carey in 1875, it envisioned a mosaic of selenium calls on which the picture to be transmitted would be focused by a lens system. At the receiving end there would be a similarly arranged mosaic made up of electric lights. Each selenium cell would be connected by an individual wire to the similarly placed light in the receiving mosaic. Light falling on the selenium cell would reproduce the original picture, had the necessary amplifiers and the right kind of lights been availablr, this system would have workrd. But it also would have required an imoractical number of connecting wires. Carey recognized this and in a second proposed to “scan” the cells-transmitting the signal from each cell to its associated light, in turn, over a single wire. If this were done fast enough, the retentive power of the eye would cause the resultant image to be seen as a complete picture. 41. Which of the following is the best title for the passage? A. Television in the Electronic Era B. First Steps in the Invention of Television C. The Art of Television D. Harmful Effects of Television Viewing 42. In line 1, the word “being” could best be replaced by _____. A. place B. creature C. subsistence D. existence 43. An important discovery in earlyteleviosion was the electrical resistance of _____. A. mosaics B. the human eye C. lenses D. the element selenium 44. In 1875, Carey suggested that the human eye envisioned a mosaic of selenium cells on which the picture to be transmitted would be focused by ______. A. wire B. electric lights C. a lens system D. amplifiers 45. Following are the reasons why the first scheme for television was abandoned except _____. A. he lacks an effective assistant B. the necessary amplifers were unavailable C. the proper lights were unavailable D. the number of connecting wires is impractical |
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| 第8题：You（）thisexerciseinwrittenform.I'llgiveyouthekey. A.don'tneeddoing B.needn'tdoing C.don'tneedtodo D.needn'ttodo |
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| 第9题： He____his feet on the ground to shake off the snow from his boots before he entered the house. A.kicked B.stamped C.swayed D.stretched |
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| 第10题：Inview（）risinglaborcost,manycompanieshaveturnedtoautomation. A.of B.for C.to D.that |
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| 第11题：The boy was injured when a firework（）in his face. A.went out B.went off C.went round D.went up |
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| 第12题：When two people feel the same way about each other, their feeling are （）. A. liable B. visible C. typical D. mutual |
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| 第13、14、15、16、17题：T[ornadoes,whirlwinds,and watersprouts are rotating funnel cloud air masses of small diameter.They are differentiated by the intensity of their rotation and by the surfaces that they traverse.Though tornadoes and whirlwinds both travel over land masses,whirlwinds are atmospheric systems smaller than tornadoes.Watersprouts are tornadoes that form or pass over a water surface.A tornado is a powerful vortex or “twister” whose rotational speeds are estimated to be near 300 miles per hour.The first visible indication of tornado development is usually a funnel cloud.As this funnel dips earthward,it becomes darker because of the debris that is forced into its intensifying vortex.Some tornadoes give no visible warning until their destruction strikes the unsuspecting victim.Tornadoes often occur in groups,and several twisters sometimes descend from the same cloud base.The forward speed of a tornado is normally 30 to 40 miles per hour.In the short time that it takes to pass,a tornado can cause fantastic destruction.There have been cases reported in which blades of straw were embeded in fence posts. 31. How are tornadoes distinguished from whirlwinds? A.Whirlwinds rotate in a different direction than tornadoes do. B.Tonadoes travel over land and whirlwinds over water. C.Tonadoes are larger than whirlwinds. D.Only tornadoes are funnelshaped. 32. Why do tornadoes appear to be dark? A.They occur only at night. B.They are funnel-shaped. C.They pick up debris from the ground. D.They are water-laden. 33. According to the passage,which of the following behaviors is frequently characteristic of funnel clouds? A.Descending from different cloud bases. B.Occurring in isolated areas. C.Lasting a long time. D.Occurring in groups. 34. According to the passage,some tornadoes take people unaware because they__. A.produce a sound similar to thunder. B.cannot be seen until it is too late. C.look so much like other clouds. D.carry so many large pieces of debris. 35. The author refers to straw embeded in fence posts in order to show __. A.where tornadoes occur. B.who makes reports about tornadoes. C.when tornadoes take form. D.how tornadoes affect physical objects. |
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| 第18题：WecanrelyonWilliamtocarryoutthismission,forthisjudgmentisalways（） A.unmistakable B.reliable C.unrequestionable D.healthy |
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