问题补充:
In order to find the missing child, villagers all they can over the past five hours.
A. did
B. do
C. had done
D. have been doing
答案:
A. did
B. do
C. had done
(答案→)D. have been doing
解析:句意:在过去的5小时里,村民们为了找到丢失的孩子,一直做他们所能做的一切。over /during/in+the past /last+时间短语,经常与现在完成时连用。故选D。