Unless to speak, you should remain silent at the meeting.
A. invited
B. inviting
C. being invited
D. having invited
网友回答
(答案→)A. invited
B. inviting
C. being invited
D. having invited
解析：考查省略。当状语从句的主语与主句主语一致的时候，可以把状语从句的主语和be动词一起省略。本题在unless与invited之间省略了you are.句意：除非别人和你说话，你在会议上一致要保持沉默。