—Can you give an example to show how useful a computer is?—Sure. ___________ people get ___________ information from it every day.
It is so difficult a problem that _____ student in this class _____ work it out.
Shirley _____ a book about China last year, but I don't know whether she has finished it.
Who did the teacher have ___ an article for the wall newspaper just now?
Use an umbrella to _____ you from the rain.
--- Alice , you feed the bird today , ______?--- But I fed it yesterday .