雅思基础语法练习及答案.docx

雅思基础语法练习
1.Sciencestillacureforcancer.a.doesn’tfindc.hasn’tfoundb.haven’tfoundd.aren’tfinding2.WhilehearoutetotheIndies,ColumbusdiscoveredAmerica.a.searchedc.hadsearchedforb.wasdiscoveringd.wassearchingfor3.Existingreservesoffossilfuelby2045.a.havebeenrunoutc.isgoingtoberunoutb.willhaverunoutd.haverunout4.Ifloggingoftropicalrainforestscontinuesatthepresentrate,a30percentincreaseinatmosphericCO2bytheyear2000.a.therewillbec.therewouldbeb.theremighthavebeend.therecouldnothavebeen5.Onlybyinvestingheavilyinvalue-addedexportsfromthepresenttradeimbalance.a.thecountrycanemergec.canthecountryemergeb.thecountrymightemerged.thecountryemerged6.Themysteryofthedoublehelix,thescopeforgeneticengineeringdramaticallyincreased.a.havingsolvedc.solvingb.havingbeensolvedd.solved7.Sincethemid-’60sconsiderableresearchinembryotransplants.a.hascarriedoutc.hasbeencarriedoutb.wasdoned.wascarriedout8.severalhypotheseshavebeenadvancedforthedisappearanceofthedinosaur,noconclusiveevidencesupportsanyofthem.a.despitec.althoughb.inspiteofd.inspiteofthefact9.Untilthe16thcenturytheearthtobeflat.a.isbelievedc.believedb.hasbeenbelievedd.wasbelieved10.Ifthetemperatureofthereactor500Chighermeltdownwouldhaveoccurred.a.wasc.wasbeingb.hadbeend.had11.adequateprecautionsaretake,thereisnoriskinvolvedintheoperation.a.Althoughc.Neverthelessb.Providingd.Even12.Mysupervisoradvisedmetotheproblem.a.lookaheadc.lookoutofb.lookdownd.lookinto13.Themoreacidyouaddtothesolution,itbecomes.a.cloudierc.thecloudiestb.thecloudierd.morecloudy14.Thelecturersaid‘It’stimeyoutheliteraturereview.’a.beganc.shouldbeginb.begind.arebeginning15.Afterstudyingourexperimentalresults,thetutorsuggestedtheexperiment.a.ustorepeatc.werepeatb.thatwetorepeatd.metorepeat16.Afteryourresultsyoushouldmakeanappointmentwithyourtutor.a.youreceivingc.youhavereceivedb.youwouldhavereceivedd.youreceived17.Youtheexperimenttwice,notonce.a.shouldhavecarriedoutc.haven’tcarriedoutb.shouldn’thavecarriedoutd.couldn’thavecarriedout18.Itlooksyou’vemadeamistake.a.asc.ifb