问题

Some researchers believe that there is no doubt ____ acure for AIDS will be found.

A:which
B:that
C:what
D:whether

正确答案是：

同类题型

earnt both business and history, but she knows________of them well, thoughshe can speak on subjects in general.

ate of Fortune, from ____top visitorscan enjoy a wonderful sea view, will attract lots of tourists.

_______this problem, they don’t know how to deal with it. [ ]

The opening ceremony of the 11thNational Games, ______ in Jinan, Shandong Province from Oct.15-28 was highlypraised.

__ brushing my teeth twice a day.