廣東省2012屆高三英語二輪復習專題訓練：閱讀理解（21）閱讀下列短文，從每題所給的A.B.C和D項中，選出最佳選項，并在答題卡上將該項涂黑。AManyyearsagomystudentaskedmethequestion,"Mrs.Kindred,whydoyouteach?"Withouttakingtimetoreflect,Ianswered,"BecausesomedayImightsaysomethingthatmightmakeadifferenceinsomeone'slife."EventhoughIwassincere,thatwasn'taverygoodanswerandmystudentdidn'tletitslide."Letmegetthisstraight,"hesaid,"Youwenttocollegeforfouryearssoyoucouldcomehereeverydaybecauseyouhavethehopethatsomedayyoumightsaysomethingthatwillinfluencesomeone?"HeshookhisheadasifIwerecrazyandwalkedawaylookingconfused.I'moneofthosepeoplewholookbackandwishtheyhadsaidsomethingsmartorwitty,orswift.EventhoughthatparticularstudentmightnolongerwonderwhyIteach,therearedayswhenIwonder.Onthosedays,IremindmyselfoftherealreasonsIteach:It'sinmyblood.Mymotherwasmymostinfluentialteacher,andshewasa6thgradereadingteacheruntilherdeathin1990.Sheinstilled(逐漸灌輸)inmealoveofreadingandtheknowledgethateducationopensdoors.Teachingisawaytomakeadifference.Ifyouthrowastoneinapondtheripplesgoonandonuntiltheyreachtheshore.Youcan'thaverippleswithouta"stone."Goodteachersthrowstonesthatmakeapositivedifference,andthat'swhatItrytodo.Igenuinelyloveteenagers.IwanttosharewithotherswhatIknowandwhatIhavelearnedthroughtheyears.Lifeisfullofupsanddowns,andifIcanhelpstudentsavoidsomepotholesontheroadoflife,Iwanttodoso.Ifthey'llallowmetocelebratetheirvictorieswiththem,Iwanttodotoo.Teachingisn'tforeveryone,butIknowImadetherightcareerchoice.1.Whydidthestudentcontinuetoaskthequestionaboutthewriter’sbeingateacher?A.Becausehethoughtheranswerwasunbelievable.B.Becausethewriterwasinsincere.C.Becausethestudentwasnaughty.D.Becausetheanswerwasdifficulttounderstand.2.Whatdoyouthinkofthewriter?A.Stupid. B.Honest. C.Conservative（保守的）. D.Polite.3.Accordingtothetext,whichofthefollowingisNOTtrue?A.Thewriter’smotherhasthegreatestinfluenceonher.B.Thewriter’sanswermadethestudentconfused.C.Inthewriter’sopinion,somepeopleintheworldareunfittoteach.D.Thewriterannoyedthestudentwhoaskedthequestion.4.Wecaninferfromthetextthat_________.A.thewriterwasalsoagoodteacherinschoolB.thewriteroftenplayswithherstudentsbesideapondC.thewriterdevotesherselftoteachingandherstudentsD.thewriteroftenaccompaniesthestudentsontheirwayhome5.What’sthemainideaofthetext?A.Astudent’ssillyquestion. B.Agoodteacherwholikesstudents.C.Aconfusedstudent. D.ThereasonwhyIteach.BCanpeoplechangetheirskincolorwithoutsufferinglikepopkingMichaelJackson?Perhapsyes.Scientistshavefoundthegenethatdeterminesskincolor.Thegenecomesintwoversions,oneofwhichisfoundin99percentofEuropeans.Theotherisfoundin93to100percentofAfricans,researchersatPennsylvaniaScientistshavechangedthecolorofadark-stripedzebrafish（斑馬魚）touniformgoldbyinsertingaversionofthepigment(色素)geneintoayoungfish.Aswithhumans,zebrafishskincolorisdeterminedbypigmentcells,whichcontainmelanin(黑色素).Thenumber,sizeanddarknessofmelaninperpigmentcelldetermineskincolor.Itappearsthat,likethegoldenzebrafish,light-skinnedEuropeansalsohaveamutation(變異)inthegeneformelaninproduction.Thisresultsinlesspigmentedskin.However,KeithCheng,leaderoftheresearchteam,pointsoutthatthemutationisdifferentinhumanandzebrafishgenes.HumansacquireddarkskininAfricaabout1.5millionyearsagotoprotectbodiesfromultra-violetraysofthesun(太陽光紫外線),whichcancauseskincancer.ButwhenmodernhumansleaveAfricatoliveinnorthernlatitudes,theyneedmoresunlightontheirskintoproducevitaminD.Sotherelatedgenechanges,accordingtoCheng.AsianshavethesameversionofthegeneasAfricans,sotheyprobablyacquiredtheirlightskinthroughtheactionofsomeothergenethataffectsskincolor,saidCheng.Thenewdiscoverycouldleadtomedicaltreatmentsforskincancer.ItalsocouldleadtoresearchintowaystochangeskincolorwithoutdamagingitlikechemicaltreatmentdidonMichaelJackson.6.Thepassagemainlytellsusthat________.A.peoplecannotchangetheirskincolorwithoutanypainB.thenewdiscoverycouldleadtoresearchintowaystochangeskincolorsafelyC.popkingMichaelJacksonoftenchangedhisskincolorashelikedD.scientistshavefoundoutthatpeople’sskincolorisdeterminedbythegene7.Itcanbeinferredfromthepassagethat________.A.nowadayspeoplewhowanttochangetheirskincolorhavetosufferalotfromthedamagecausedbythechemicaltreatmentB.EuropeansandAfricanshavethesamegeneC.thenewdiscoverycouldhelptofindmedicaltreatmentsforskincancerD.therearetw