for a bus, I was reading a magazine.
A. While was waiting
B. While I waiting
C. While I am waiting
D. While waiting
网友回答
A. While was waiting
B. While I waiting
C. While I am waiting
(答案→)D. While waiting
解析:有些时间状语从句中的谓语动词如果有动词be,主语又与主句的主语一致,或主语是it是,则从句的主语和谓语的一部分(特别是动词be)常常可以省略。