In the past few years, Chinese scientists ________ great success in the field of space flight.
| A．achieved | B．have achieved | C．won | D．had won |
.
___________is hard is to do good all one's life and never do anything bad.
| A．He | B．It | C．That | D．What |
.
—What are you busy with?
—The conference___________in our city next week, as you know.
| A．held | B．will be held | C．be holding | D．to be held |
.
Just because they make more money than I do, ___________they seem to look down on me.
| A．so | B．and | C．but | D．不填 |
.
—I’ve never found a better job and I’m so glad.
—___________.
| A．I don’t think so | B．Too bad |
| C．Congratulations | D．Don’t worry |
.
—Have you seen___________pen? I left it here this morning.
—Is it___________black one? I think I saw it somewhere.
| A．a, the | B．the, the | C．a, a | D．the, a |