考研英语七选五模拟练习

凯程考研集训营，为学生引路，为学员服务！考研英语七选五模拟练习Directions:Inthefollowingtext,somesentenceshavebeenremoved.ForQuestions41-45,choosethemostsuitableonefromthelistA-Gtofitintoeachofthenumberedblanks.Therearetwoextrachoices,whichdonotfitinanyoftheblanks.MarkyouranswersonANSWERSHEET1.(10points)LongbeforeManlivedontheEarth,therewerefishes,reptiles,birds,insects,andsomemammals.Althoughsomeoftheseanimalswereancestorsofkindslivingtoday,othersarenowextinct,thatis,theyhavenodescendantsalivenow.41)________Veryoccasionallytherocksshowimpressionofskin,sothat,apartfromcolor,wecanbuildupareasonablyaccuratepictureofananimalthatdiedmillionsofyearsago.Thekindofrockinwhichtheremainsarefoundtellsusmuchaboutthenatureoftheoriginalland,oftenoftheplantsthatgrewonit,andevenofitsclimate.42)________.Nearlyallofthefossilsthatweknowwerepreservedinrocksformedbywateraction,andmostoftheseareofanimalsthatlivedinornearwater.Thusitfollowsthattheremustbemanykindsofmammals,birds,andinsectsofwhichweknownothing.43)________Therewerealsocrab-likecreatures,whosebodieswerecoveredwithahornysubstance.Thebodysegmentseachhadtwopairsoflegs,onepairforwalkingonthesandybottom,theotherforswimming.Theheadwasakindofshieldwithapairofcompoundeyes,oftenwiththousandsoflenses.Theywereusuallyaninchortwolongbutsomewere2feet.44)________.Ofthese,theammonitesareveryinterestingandimportant.Theyhaveashellcomposedofmanychambers,eachrepresentingatemporaryhomeoftheanimal.Astheyounggrewlargeritgrewanewchamberandsealedoffthepreviousone.ThousandsofthesecanbeseenintherocksontheDorsetCoast.45)________.About75millionyearsagotheAgeofReptileswasoverandmostofthegroupsdiedout.Themammalsquicklydeveloped,andwecantracetheevolutionofmanyfamiliaranimalssuchastheelephantandhorse.Manyofthelatermammals,thoughnowextinct,wereknowntoprimitivemanandwerefeaturedbyhimincavepaintingsandonbonecarvings.[A]Theshellfishhavealonghistoryintherockandmanydifferentkindsareknown.[B]Nevertheless,weknowagreatdealaboutmanyofthembecausetheirbonesandshellshavebeenpreservedintherocksasfossils.Fromthemwecantelltheirsizeandshape,howtheywalked,thekindoffoodtheyate.[C]Thefirstanimalswithtruebackboneswerethefishes,firstknownintherocksof375millionyearsago.About300millionyearsagotheamphibians,the凯程考研集训营，为学生引路，为学员服务！animalsabletolivebothonlandandinwater,appeared.Theyweregiant,sometimes8feetlong,andmanyofthemlivedintheswampypoolsinwhichourcoalseam,orlayer,formed.Theamphibiansgaverisetothereptilesandfornearly150millionyearstheseweretheprincipalformsoflifeonland,inthesea,andintheair.[D]Thebestindexfossilstendtobemarinecreatures.Theseanimalsevolvedrapidlyandspreadoverlargeareasoftheworld.[E]Theearliestanimalswhoseremainshavebeenfoundwereallverysimplekindsandlivedinthesea.Laterformsaremorecomplex,andamongthesearethesea-lilies,relationsofthestar-fishes,whichhadlongarmsandwereattachedbyalongstalktotheseabed,ortorocks.[F]Whenananimaldies,thebody,itsbones,orshell,mayoftenbecarriedawaybystreamsintolakesortheseaaridtheregetcoveredupbymud.Iftheanimallivedintheseaitsbodywouldprobablysinkandbecoveredwithmud.Moreandmoremudwouldfalluponituntilthebonesorshellbecomeembeddedandpreserved.[G]Manyfactorscaninfluencehowfossilsarepreservedinrocks.Remainsofanorganismmaybereplacedbyminerals,dissolvedbyanacidicsolutiontoleaveonlytheirimpression,orsimplyreducedtoamorestableform.七(六)选五41.B42.F43.E44.A45.C凯程考研集训营，为学生引路，为学员服务！小提示：目前本科生就业市场竞争激烈，就业主体是研究生，在如今考研竞争日渐激烈的情况下，我们想要不在考研大军中变成分母，我们需要：早开始+好计划+正确的复习思路+好的辅导班（如果经济条件允许的情况下）。2017考研开始准备复习啦，早起的鸟儿有虫吃，一分耕耘一分收获。加油！