如图(a)，一弹簧上端固定在支架顶端，下端悬挂一托盘：一标尺由游标和主尺构成，主尺竖直固定在弹簧左边;托盘上方固定有一能与游标刻度线准确对齐的装置，简化为图中的指针。现要测量图(a)中弹簧的劲度系数，当托盘内没有砝码时，移动游标，使其零刻度线对准指针，此时标尺读数为1.950cm;当托盘内放有质量为0.100kg的砝码时，移动游标，再次使其零刻度线对准指针，标尺示数如图(b)所示，其读数为_______cm。当地的重力加速度大小为9.80m/s2，此弹簧的劲度系数为________N/m(保留3位有效数字)。
3.775、53.7
实验所用的游标卡尺精度为0.05mm，游标卡尺上游标第15条刻度线与主尺刻度线对齐，根据游标卡尺的读
John'sscoreonthetestisthehighestintheclass;he____lastnight.
I’veneverbeenoutofChina___________.Whataboutyou?
____Thewaterleftinthekettle,thedoctorputseveralthingsheunwrappedfromahandkerchief.
Idon’tunderstand____believehim.
Insomecountrieswhereracialprejudiceisacute,violencehassocometobetakenforgrantedasameansofsolvingdifferences,thatitisnotevenquestioned.Therearecountrieswherethewhitemanimposeshisrulebybruteforce;therearecountrieswheretheblackmanprotestsbysettingfiretocitiesandbylootingandpillaging.Importantpeopleonbothsides,whowouldinotherrespectsappeartobereasonablemen,getupandcalmlyargueinfavorofviolence–asifitwerealegitimatesolution,likeanyother.Whatisreallyfrightening,whatreallyfillsyouwithdespair,istherealizationthatwhenitcomestothecrunch,wehavemadenoactualprogressatall.Wemaywearcollarsandtiesinsteadofwar-paint,butourinstinctsremainbasicallyunchanged.Thewholeoftherecordedhistoryofthehumanrace,thattediousdocumentationofviolence,hastaughtusabsolutelynothing.Wehavestillnotlearntthatviolenceneversolvesaproblembutmakesitmoreacute.Thesheerhorror,thebloodshed,thesufferingmeannothing.Nosolutionevercomestolightthemorningafterwhenwedismallycontemplatethesmokingruinsandwonderwhathitus.Thetrulyreasonablemenwhoknowwherethesolutionsliearefindingitharderandherdertogetahearing.Theyaredespised,mistrustedandevenpersecutedbytheirownkindbecausetheyadvocatesuchapparentlyoutrageousthingsaslawenforcement.Ifhalftheenergythatgoesintoviolentactswereputtogooduse,ifoureffortsweredirectedatcleaninguptheslumsandghettos,atimprovingliving-standardsandprovidingeducationandemploymentforall,wewouldhavegonealongwaytoarrivingatasolution.Ourstrengthissappedbyhavingtomopupthemessthatviolenceleavesinitswake.Inawell-directedeffort,itwouldnotbeimpossibletofulfilltheidealsofastablesocialprogramme.Thebenefitsthatcanbederivedfromconstructivesolutionsareeverywhereapparentintheworldaroundus.Genuineandlastingsolutionsarealwayspossible,providingweworkwithintheframeworkofthelaw.Beforewecanevenbegintocontemplatepeacefulco-existencebetweentheraces,wemustappreciateeachother'sproblems.Andtodothis,wemustlearnaboutthem:itisasimpleexerciseincommunication,inexchanginginformation."Talk,talk,talk,"theadvocatesofviolencesay,"allyoueverdoistalk,andwearenonethewiser."It'sratherlikethestoryofthefamousbarristerwhopainstakinglyexplainedhiscasetothejudge.Afterlisteningtoalengthyargumentthejudgecomplainedthatafterallthistalk,hewasnonethewiser."Possible,mylord,"thebarristerreplied,"nonethewiser,butsurelyfarbetterinformed."Knowledgeisthenecessaryprerequisitetowisdom:theknowledgethatviolencecreatestheevilsitpretendstosolve.
1.Whatisthebesttitleforthispassage?
[A]AdvocatingViolence.
[B]ViolenceCanDoNothingtoDiminishRacePrejudice.
[C]ImportantPeopleonBothSidesSeeViolenceAsaLegitimateSolution.
[D]TheInstinctsofHumanRaceAreThirstyforViolence.
2.Recordedhistoryhastaughtus
[A]violenceneversolvesanything.[B]nothing.[C]thebloodshedmeansnothing.[D]everything.
3.Itcanbeinferredthattrulyreasonablemen
[A]can'tgetahearing.
[B]arelookeddownupon.
[C]arepersecuted.
[D]Havedifficultyin
advocatinglawenforcement.
4."Hewasnonethewiser"means
[A]hewasnotatallwiseinlistening.
[B]Hewasnotatallwiserthannothingbefore.
[C]Hegainsnothingafterlistening.
[D]Hemakesnosenseoftheargument.
5.Accordingtheauthorthebestwaytosolveraceprejudiceis
[A]lawenforcement.[B]knowledge.[C]nonviolence.[D]Moppinguptheviolentmess.
