At the lecture,we were asked not to speak until__C___.

题目

At the lecture,we were asked not to speak until__C___.
A.being spoken to
B.spoken
C.spoken to
D.speaking to
说清楚选择答案及原因,不要用排除法最好说清楚为什么不能选别的.
不说原因做对了也不给分.

答案

当从句主语与主句主语一致,且从句中含动词be的形式时,从句主语与动词be可一并省略.例如：He didn’t speak until (he was) spoken to.直到有人跟他说话他才开口.
不用给分,注意礼貌.