1、Both his parents look sad .Maybe they _________what's happened to him .(呼和浩特)

问题描述:

1、Both his parents look sad .Maybe they _________what's happened to him .(呼和浩特)
A.knew B.have known C.must know D.will know 选哪一个?

B
其他代进去都不通丫...
他的父母看上去都很伤心,好像已经知道他发生了什么事