单项选择题

We（）on it for many hours but we have not yet reached any conclusion.

A．work
B．have been worked
C．have been working
D．are working

<上一题目录下一题>

热门试题

单项选择题

I have no idea（）you are a famous football player.

A．which
B．why
C．what
D．that

相关试题