单项选择。Both his parents look sad.Maybe they
问题详情:
单项选择。
Both his parents look sad . Maybe they _________what's happened to him .
A. knew B. have known C. must know D know
【回答】
B
知识点:动词时态
题型:选择题
问题详情:
单项选择。
Both his parents look sad . Maybe they _________what's happened to him .
A. knew B. have known C. must know D know
【回答】
B
知识点:动词时态
题型:选择题