时间状语：always, usually, often, sometimes, every week (day, year, month„),
once a week, on Sundays, etc.
时间状语：ago, yesterday, the day before yesterday, last week(year, night, month„), in 1989, just now, at the age of 5, one day, long long ago, once upon a time, etc.
时间状语：now, at this time, these days, etc.
时间状语：at this time yesterday, at that time或以when引导的谓语动词是一般过去时的时间状语等。
否定形式：was/were + not + doing.
时间状语：recently, lately, since„for„,in the past few years, etc.
基本结构：have/has + done
否定形式：have/has + not +d one.
1. --- Oh, dear. I forgot the air tickets.
--- You ______ something.
A. have left B. are always leaving
C. are leaving D. always left
2. --- I ______ so busily recently that I ______ no time to help you with your math.
--- That’s OK. I can manage it by myself.
A. have been working; have B. have worked; had
C. am working; will have D. had been working; had had
3. Remember to send me a photo of us next time you ______ to me.
A. are writing B. will write
C. has written D. write
4. He ______ at the meeting, but his heart attack prevented him.
A. will speak B. is going to speak
C. had to speak D. was going to speak
5. --- I beg your pardon, but I didn’t quite catch you.
--- Oh, I ______ myself.
A. am talking to B. talked about
C. have talked to D. was talking to
6. I ______ ping-pong quite well, but I haven’t had time to play since the New Year.
A. will play B. have played
C. played D. play
7. I first met Tom 10 years ago. He ______ in a radio factory at that time.
A. had worked B. has worked
C. was working D. has been working
8. --- What ______ when I phoned you?
--- I ______ my work, and I wanted to go out.
A. have you done; finished B. were you doing; have finished
C. did you do; had just finished D. were you doing; had just finished