填空:Unless[ ](invite)to speak,you should remain silent at the conference.

题目

填空:Unless[ ](invite)to speak,you should remain silent at the conference.

答案

这是一个省略句,从句应该是被动的,意思是：
除非你被邀请说话,否则在开会时就应该保持沉默.
填invited
相当于：
Unless you are invited to speak,you should remain silent at the conference.