英语阅读有all的选项可以选吗?B为何不可还有75的C.D

SincetheInternethascomeintohomes,thedailylifehasneverbeenthesameagain.ButthethingthatworriesmostofusisthatwecangetvirusesfromtheInternet.Butcanwecatchvirusesonourcellphones?AnewstudyinthejourneySciencesaysyes,butthespreadofsuchmobilesoftwarethatcanbringharmtoourcellphoneswon’treachdangerouslevelsuntilmorecellphonesareonthesameoperatingsystem.

Computersareeasilyattackedbyvirusesbecausetheysharedata,especiallyovertheInternet.Ofcourse,nowadays,morepeopleareusingtheircellphonesmoreandmorefrequently.Theyusethemforemailing,textmessaginganddownloadingtroublesomeringtones,etc.soitisobviousthatcellphonevirousesareathreat,aswell.

Scientistsusednamelesscalldatafrommorethansixmillioncellphoneuserstohelpmodelapossibleoutbreak.AndtheyconcludedthatvirousesthatspreadfromphonetophonebyBluetootharenotmuchconcerned,becauseusershavetobeinclosephysicalrelationfortheirphonesto“see”oneanother.However,virusesthatspreadthroughmultimediamessagingservicescanmovemuchfaster,becausetheycancomeindisguise,suchasacooltunesentbyafriend.Thegoodnewsisthattobeeffective,thesevirusesneedtheirvictimstoallusethesameoperatingsystem,whichnotenoughofusdo.BecausethereisnoMicrosoftoperatingsystemformobilephones,yet.Thankgoodness.

73.When_______,cellphonevirusescanbedangerous.

A.allthecellphonesworkonthesameoperatingsystem

B.Microsoftoperatingsystemforcellphonesiscreated

C.userscanseeeachotheronthephone

D.Bluetoothiswidelyused

75.Wecanlearnfromthepassagethat_______.

A.itisimpossibletocatchvirusesonourcellphones

B.cellponesarenotwellconnectedwiththeInternet

C.itisdangerousforpeopletodownloadringtonestocellphones

D.morethanoneoperatingsystemisavailableforcellphoneusersnow

我的all意思是题目中出现all等太绝对的词的字眼啊不是Alloftheabove。