雅思基础语法练习及答案.doc

此文档收集于网络，如有侵权请联系网站删除雅思基础语法练习now and then 偶尔；有时1.Science still a cure for cancer.obesity n. 过度肥胖necessity n. 必要性；需要vt. 减轻（痛苦；忧虑）a.soil n. 土壤organization n. 组织；机构；团体essential adj. 最重要的；不可缺少的；doesnt find 作）；俯冲permit vt. & vi. 许可；允许；准许tradition n. 传统；风俗c.hasnt foundb.havent foundd.arent finding2.While he a route to the Indies, Columbus discovered America.a.searched c.had searched forb.was discoveringd.was searching for3.Existing reserves of fossil fuel by 2045.a.have been run out c.is going to be run outb.will have run outd.have run out4.If logging of tropical rainforests continues at the present rate, a 30 per cent increase in atmospheric CO2 by the year 2000.a.there will be c.there would beb.there might have beend.there could not have been5.Only by investing heavily in value-added exports from the present trade imbalance.a.the country can emerge c.can the country emergeb.the country might emerged.the country emerged6.The mystery of the double helix , the scope for genetic engineering dramatically increased.a.having solvedc.solvingb.having been solvedd.solved7.Since the mid-60s considerable research in embryo transplants .a.has carried out c.has been carried outb.was doned.was carried out8. several hypotheses have been advanced for the disappearance of the dinosaur, no conclusive evidence supports any of them.a.despite c.althoughb.in spite ofd.in spite of the fact9.Until the 16th century the earth to be flat.a.is believedc.believedb.has been believedd.was believed10.If the temperature of the reactor 500C higher meltdown would have occurred.a.wasc.was beingb.had been d.had11. adequate precautions are take, there is no risk involved in the operation.a.Although c.Neverthelessb.Providing d.Even12.My supervisor advised me to the problem.a.look aheadc.look out ofb.look downd.look into13.The more acid you add to the solution, it becomes.a.cloudier c.the cloudiestb.the cloudierd.more cloudy14.The lecturer said Its time you the literature review.a.beganc.should beginb.begin d.are beginning15.After studying our experimental results, the tutor suggested the experiment.a.us to repeatc.we repeatb.that we to repeatd.me to repeat16.After your results you should make an appointment with your tutor.a.you receivingc.you have receivedb.you would have receivedd.you received17.You the experiment twice, not once.a.should have carried outc.havent carried outb.shouldnt have carried outd.couldnt have carried out18.It looks youve made a mistake.a.as c.ifb.as though d.perhaps19.After receiving her results, the student stopped .a.to worryc.worryingb.having worriedd.to be worried20.You include this section. It is not necessarya.must c.dont needb.couldntd.dont have to21.Unless an extension at least one week before the due date, it will not be given.a.you request c.you requestedb.you will requestd.requesting22.The assignment made me .a.to think hard c.think hardb.thinking hardd.thought hard23.The scientists were prohibited the danger zone.a.to enterc.enterb.entering d.from entering24. the right answer I would have got full marks.a.Had I known c.If Ill knowb.if I would have knownd.If I was knowing25.The results were convincing that we decided to publish them.a.so c.very b.suchd.so much26. way you do it, the answer is always the same.a.However c.Who everb.whicheverd.Why ever27. producing methane, the process also produces carbon monoxide.a.Apart c.Besidesb.As well d.In addition28.The biologist admitted excessive numbers of animals in laboratory tests.a.using c.being usedb.to use d.used29.A whale is a mammal, it is warm-blooded and gives milk to its young.a.whoc.which means thatb.which d.that30.He appears mino