Do you know the traffic accident ____ on a foggy moring?

问题描述:

Do you know the traffic accident ____ on a foggy moring?
A.happening
B.which happened
C.which happening
D.that was happened

选B,
如果是a,应该是车祸正在发生,可句末有“一个有雾的早上”,故排除.
如果是c,应该在两个单词中间加上was,表示过去正在发生的过去进行时.
不能是d,happen和take place“发生”在英语中都不能用被动式.be后边加动词过去分词就是被动时.