--- Look at these girls. Are ________ your friends?
--- No, I don’t know _________.
| A．they; them | B．they; they |
| C．them; them | D．them; they |
------ He is late for the meeting.
------ ______.
A. So am I B. So I am C. So I do
------ What a nice motorbike! How long have you ______ it?
------ About half a year.
A. had B. receive C. bought
There are several chemical factories ______ waste water into the river.
A. pours B. pour C. pouring
Jim has been to the Great Wall before, ______ he?
A. has B. does C. hasn’t
The city has improved a lot _________ I came here a few years ago.
A. sinceB. forC. when