问题补充:
We have done what .So don’t panic any more.
A. is doing
B. has done
C. is done
D. can be done
答案:
A. is doing
B. has done
C. is done
(答案→)D. can be done
解析:原句意思是:能够做的我们已经做过了,因此不要再惊慌了。选项A. is doing正在做(主动语态);B. has done已做了(现在完成时主动语态)C. is done被做(一般现在时被动语态)D. can be done能被做(含有情态动词的被动语态)。根据句意,故选D。