I heard it was going to become cloudy this afternoon by a storm.A. followingB. followedC

问题补充：

I heard it was going to become cloudy this afternoon, by a storm.

A. following

B. followed

C. follow

D. to follow

答案：

A. following

(答案→)B. followed

C. follow

D. to follow

解析：考查非谓语动词，根据句子结构可知，此处作状语，by可知，follow与他的逻辑主语I之间是被动关系，故选择B