阅读理解. Imaginereadingonedaythatyouhadbeenasubjectinariskyscienceexperimentwithoutknowingit.

Atschool,youhadbeenfedcereallacedwithradioactivechemicalssoscientistscouldlearnmoreabout

thedigestivesystem.Becausethefoodwasradioactive,scientistscouldeasilytraceitspaththroughthe

body.

Scientistsnowknowthatexposuretolargeamountsofradiationcancausecancer,agroupofdiseases

inwhichbodilycellsgrowwildlyoutofcontrol.Somepeoplewhowerepartoftheradiationstudieslater

developedcancerandblametheradiationforcausingthecancer.Othersareworriedtheradiationwill

somedaymakethemsick.

Somedoctorssaythat,inmanycases,suchfearsareunjustifiedbecausetheradiationdoses(剂量)used

intheexperimentsweretoosmalltocauseharm.Theyalsosaythatsincethedangersofradiationwereless

wellunderstoodthenthantheyarenow,evenresearcherswhousedhighdosesofradiationdidn'tdoanything

wrong.

Somecriticsclaimthatnoexcuseisacceptablefornotinformingsubjectsaboutthenatureofanexperiment

andgivingthemachancetorefusetoparticipate.Today,governmentrulesrequiresuchinformedagreement

wheneverastudyusespeople.1.Thepassageismainlyabout_____.A.whatkindsofexperimentcannotbedoneonpeople

B.whetheritismoraltoexperimentonpeoplewithouttellingthem

C.whatresultcanbeobtainedinaradioactiveexperiment

D.howradiationstudiesareconducted2.WhichofthefollowingstatementsisTRUEaccordingtothepassage?A.Humancellscanbeexcitedbytheradiationtogrowwildlyoutofcontrol.

B.Aslongasthedangerofradiationhasnotbeenproved,highdosesofitcanalsobeacceptable.

C.Mostcancersarecausedbyradiation.

D.Anyexposuretoradiationwillsurelycausecancer.3.Thegovernmentrulesdemand_____.A.tostopallexperimentsharmfultopeople

B.toprohibitalltheexperimentsonhumans

C.tolicenceallthetestsrelatedtohumanbeings

D.toprotect