高一英语语法 用所给词的适当形式填空

问题描述:

高一英语语法 用所给词的适当形式填空
-I didn't know you were good friends.
-You ___(can have).I have known her since she moved here.You were studying abroad then.
-Where is my dictionary?
-Somebody __(must take)it away by mistake.
He didn't hear the bell ring.he __(must be)asleep.

couldn't have
must have taken
must have been