英语问题,怎么判断?

最好有分析,为什么选这个.我是初中生,对这些有点不太懂.thankyou~

1.Itwasthere,thepolicebelieve,________shewasabletoactivatetherecordershekeptinherbag.

A、untilB、whichC、thatD、when

2.Itisnotyetknown________computerswillonedayhavevisionasgoodashumanvision.

A、whetherB、ifC、thatD、how

3.Ifyouarenow________,yououghttopaymoreattentiontoyourhealth.

A、inthefiftiesB、inyourfiftiesC、infiftiesD、inyourfifty

4.Americanshavelearnedmuchabouthewayinwhichthesystemcanbemanagedsoasto________thepeacefultransferofpowerfromonepartytotheother.

A、makeitpossibleB、makepossibleC、makepossiblyD、makeitpossibly

5.________theirdifferences,theyfellpassionatelyinlovewitheachother.

A、AsforB、OwingtoC、DespiteD、Through

6.不用说,我们现在已不是生活在传统社会.