Sales of CDs have greatly increased since the early 1990s, when people _____to enjoy the advantages of this new technology.
A. begin B. began C. have begun D. had begun
—Betty promised me to come round to keep you company today.
— But she _______. I’ve been alone all day.
A. won't B. hadn't C. hasn't D. doesn't
What do you think the children when we get home?
A. are doing B. will be doing C. do D. have d6ne
The telephone _______, but by the time I got indoors, it stopped.
A. had rung B. was ringing C. rings D. has rung
—Tom，would you please come and help us with the computer at the meeting tomorrow?
一I am sorry, but I then.
A. would have class B. will be having class
C. was going to have class D. am about to have class
I got caught in the rain and my suit____.
A. has ruined B. had ruined C. has been ruined D. had been ruined
