— Would you mind my taking this seat? — ______. A.Sorry, I can’t B.No,not at all C.It’s a pleasure
—Do you know him?—I’m sure I’ve seen him _____, but I can’t remember the right place.
What can we students do _____ the environment?
—How long have you lived in this town?—_____ 2001.
There are five people in the room, but I know _____.
Don’t give up _____ you will never succeed.