What was the___of the accident?
A.reason   B.cause   C.way   D.answer
2.I___no sooner reached home than it began to rain.
A.have   B.has   C.had   D.不填
3.The salesman persuaded us___his product.
A.buy   B.to buy   C.buying   D.bought
4.You should___the fire before going to bed.
A.put away   B.put up   C.put off   D.put out
5.It took them a long time___the problem of pollution.
A.to solve   B.solving   C.solved   D.solve
6.——What is Tom doing?  ——He is busy___his new movie.
A.for   B.in   C.with   D.from