What ____ they ____ last night?(do)
还有：He ____ (be) very ill before he _____ (die).
We _____ (not disturb) him until he ) _____ (finish) working.
When _____ the visitors _____ (arrives) last Sunday?
_____ you _____ (finish) your reading yet?
You'd better _____ some milk.(have)
Don't _____ (be) late for class next time.