In order to find the missing child，villagers all they can over the past five hours.(2012·安徽)
A. did
B. do
C. had done
D. have been doing
网友回答
A. did
B. do
C. had done
(答案→)D. have been doing
解析：考查动词时态。句意：为了找到那个丢失的孩子，在过去的五个小时里，村民们做了他们所能做的一切事情。根据句中的can及时间状语“over the past five hours”可知，此处应用现在完成进行时。