问题补充:
The fire before the fire-fighters arrived.
A. has been put out
B. was put out
C. had put out
D. had been put out
答案:
A. has been put out
B. was put out
C. had put out
(答案→)D. had been put out
解析:考查时态。根据the fire-fighters arrived用一般过去时,故大火扑灭是过去的过去,即过去完成时,用其被动形式。句意:消防员到达之前,大火已经被扑灭了。