Professor Wang will give us a lectrue on the black hole,but where and when __ yet.
A.hasn't been decided
B.haven't decided
C.isn't being decided
D.aren't decided
人气：218 ℃ 时间：2020-05-12 03:12:44
解答
A
when 和where 指的都是give us a lecture这一件事的两个方面,用单数.
推荐
猜你喜欢
