No matter how bright a talker you are, there are times when it’s better silent.
A. remain
B. be remaining
C. having remained
D. to remain
网友回答
A. remain
B. be remaining
C. having remained
(答案→)D. to remain
解析：考察形式主语。It是形式主语，真正的主语是to remain silent.句意：无论你是一个多么聪明的人。有很多时候保持沉默都是最好的。