4.给定A={1,2,3,4},A上的关系R={(1,3),(1,4),(2,3),(2,4),(3,4)}满足的性质是()
C
III.Reading.(2x3=6)GileadSciencesisreportingsomepreliminaryresultsfromtheuseofitsantiviraldrugremdesivirintreatingpatientswithCOVID-19.Thestudy,publishedFridaybytheNewEnglandJournalofMedicine,evaluatedtheresponseof53patientsgivenremdesivironacompassionateusebasis.Thirty-sixshowedclinicalimprovement,whileeightgotworse.Patientswhowerenotonaventilatortendedtodobetterthanthosewhowere.Sevenofthe53died.Allwereinseriousconditionandneededsomekindofoxygensupport,includingmechanicalventilation.ThepatientsreceivedthedrugbetweenJan.25andMarch7ofthisyear.Halfthepatientswerefollowedfor18daysorless.Thepatientswerestudiedinhospitalsaroundtheworld:22intheUnitedStates,22inEuropeorCanadaand9inJapan.Morethanhalfthepatientsinthestudyexperiencedsideeffectfromthedrug,rangingfromarashanddiarrheatoacutekidneyinjury.Astheauthorsnote,severalfactorsmakeithardtointerprettheresultsonthestudy.Thesmallnumberofpatients,therelativelyshortdurationofthefollow-upandthelackofacontrolgroup—peoplewhoreceivedaplaceboinsteadoftheactivedrug.Severallargecontrolledstudiesareunderwaythatcouldprovidemoredefinitiveevidenceofwhetherthedrugisusefulornot,andunderwhatcircumstances.11.Whatisremdesivir?
以下程序的输出结果是ls1=[1,2,3,4,5]ls2=[3,4,5,6,7,8]cha1=[]foriinls2:ifinotinls1:cha1.append(i)print(cha1)