2012年12月英语四级选词填空专项训练

enfour

        　　第21页：UNIT 21
        　　UNIT 21
        　　Like most parents, geologist Brain Atwater worries about his daughter’s safety. But these days, he has an unusual concern; The public school she 11 in Seattle has unreinforced brick walls, a 12 being easy to collapse during earthquakes. The same 13 of walls crushed hundreds of thousands of people during the 1976 Tangshan quake in China.
        　　A decade ago, Atwater would have paid little notice to schoolroom walls. But over the last several years, he and other scientists have found 14 signs that the Pacific Northwest has experienced giant quakes in the distant past and that the area may be headed for a destructive shock in the near future.
        　　At a meeting of the American Geophysical Union in December, researchers discussed the 15 uncovered evidence of quake potential in the Pacific Northwest. While some remain unconvinced that huge earthquakes—with magnitudes of 8 or higher—do indeed 16 this region, a growing number consider such shocks a serious possibility.
        　　What’s worrisome, they say, is that northwestern cities such as Portland, Seattle and Vancouver have not prepared for earthquakes of this magnitude, which could shake the region’s 17 centers with enough force to make the recent San Francisco area damage seem 18 in comparison.
        　　"I think it’s quite true to say that nothing has really been designed with one of these earthquakes in mind," says seismologist Paul Somerville of Woodward. At the meeting, Somerville and his colleagues 19 estimates of the degree of shaking. Portland and Seattle would suffer during such a 20 earthquake.
        　　
       

A. massive	B.	recently	C.	construction	D.	displayed
E. relatively	F.	attends	G.	type	H.	strike
I. structure	J.	participates	K.	excessive	L.	mild
M. disturbing	N.	population	0.	presented

         
            
            

enthree

        　　第22页：UnitTwenty-Two
        　　Unit Twenty-Two
        　　Passage 2
        　　During the nineteenth and twentieth centuries, migrations have taken place within 11 countries; the cities with their industries have attracted people away from the country. The possibility of earning a fixed 12 in a factory or office was more attractive than the possibility of staying on the farm and having one’s work 13 by frost, storms, or droughts. Furthermore, the
        　　development of agricultural machinery made it possible for fewer people to do the same 14 of work.
        　　Thus, at the same time when the industrial revolution made it possible to produce goods more 15 and more quickly in factories, agricultural revolution also took place. Instead of leaving fields empty every third year, farmers began to plant clover or some other crop that would 16 the soil. Instead of using only animal fertilizer, farmers began to use chemical fertilizers to keep the soil
        　　 150 ?
        　　rich. These methods have enabled French farmers, for example, to get five times as much wheat as was 17 from the same land two centuries ago.
        　　In many countries farmers find it more 18 to raise only one crop or one kind of animal. They choose the kind that gives the best results. Then they sell all that they produce, instead of trying to grow a little of everything and consume what they grow. This is a more feasible type of 19 because modern methods and machinery are adapted to specific animals and specific crops. Therefore, it would be too expensive to do all the work by hand, or to buy the 20 needed for several different kinds of farming.
        　　A. salary E. deserted I. equivalent M. destroyed
        　　B. freely F. operation J. enrich N. certain
        　　C. profitable G.amount K. fruitful O. cheaply
        　　D. obtained H. payment L. equipment
       
            
            

ensix

        　　第23页：Unit Twenty-Three
        　　Unit Twenty-Three
        　　Passage 2
        　　The difference between a liquid and a gas is obvious under the conditions of temperature and pressure commonly found at the surface of the Earth. A liquid can be kept in an open container and fill it to the level of a free surface. A gas forms no free surface but tends to diffuse throughout the 11 available; it must therefore be kept in a closed container or held by a gravitational field, as in the 12 of a planet’s atmosphere. The distinction was a 13 feature of early theories describing the phases of matter. In the nineteenth century, for example, one theory maintained that a liquid could be "dissolved" in a vapor without losing its identity, and another theory 14 that the two phases are made up of different kinds of molecules. The theories now prevailing take a quite different approach by emphasizing what liquids and gases have in 15 They are both forms of matter that have no 16 structure, and they both flow readily.
        　　The fundamental similarity of liquids and gases becomes clearly apparent when the temperature and pressure are 17 somewhat. Suppose a closed container 18 filled with a liquid is heated. The liquid expands, or in other words becomes less dense; some of it evaporates. In contrast, the vapor above the liquid surface becomes denser as the evaporated molecules are 19 to it. The combination of temperature and pressure at which the densities become 20
        　　is called the critical point.
        　　
       

A. added	B. case	C.	prominent	D.	held
E. equal	F. partially	G.	example	H.	previous
' I. space	J, lifted	K.	permanent	L.	particularly
M. extended	N. raised	0.	common

         
            
            

entwo

        　　第24页：UnitTwenty-Four
        　　Unit Twenty-Four
        　　Passage 2
        　　Scientists at Sussex University appear to be on the way to 11 how the mosquito, carrier of diseases such as malaria and yellow fever, homes in on its target. The problem is that they have found that the best way to avoid being bitten is: stop breathing, stop sweating, and keep down the temperature of your immediate surroundings. 12 the first suggestion is impossible and the others very difficult.
        　　Scientists have found that there are three 13 stages in a mosquito’s assault. Stage one is at fifty feet away, when the insect first smells a man or a animal to 14 . Stage two is thought to come into operation about twenty-five feet from the target, when the insect becomes guided by the carbon dioxide breathed out by the intended victim. Stage three is when the mosquito is only a matter of inches from its 15 the warmth and moisture given off by the victim is the final clue.
        　　The researchers then * 16 how repellents interfere with its three-stage attack. They found repellents act more subtly than by just giving off a nasty smell. A Canadian researcher says that repellents appear to 17 mosquitoes first when it is following the carbon dioxide and second during the final approach, where the warmth and moisture are the insect’s 18 .
        　　Air pervaded by one of the many chemical repellents stops the mosquito reacting to the victim’s carbon dioxide, and the repellent seems to affect the tiny hairs with which the insect senses moisture in the air. The sensors are blocked so that the 19 does not know whether it is flying through a moist current, or
        　　the sensors are made to send the 20 signals.
        　　
       

A. examined	B.	animal	C.	wrong	D.	insect
E. bite	F.	Unfortunately	G.	inventing	H.	distinct
I. prey	J.	guide	K.	checked	L.	definite
M. Unnecessarily	N.	confuse	O.	discovering