I'm sure he must ( )behind that tree.

问题描述:

I'm sure he must ( )behind that tree.
0 - 离问题结束还有 14 天 23 小时
I'm sure he must ( )behind that tree.
0 - 解决时间:2009-9-13 23:02
A be hidden B be hidding C have hidden D have been hiding

括号处填 a