问题

I know Mr Brown；we _____ to each other at aninternational conference.

A:are introduced
B:have been introduced
C:were introduced
D:had been introduced

正确答案是：

同类题型

–Don’t _____ this plan to the public until we give you the go-ahead.–OK. I will not.

We are confident that the environment________by our further efforts to reduce pollution(2013·辽宁，30)

What’s that—________.

Can you come here today or tomorrow— I’m afraid _________ day is possible.

He won’t give up ______ he ______ in achieving his dreams.