He unwisely but he was at least trying to do something helpful.A. may have acted B. must

问题补充：

He unwisely, but he was at least trying to do something helpful.

A. may have acted

B. must have acted

C. should have acted

D. would act

答案：

(答案→)A. may have acted

B. must have acted

C. should have acted

D. would act

解析：句意：他的行为也许不明智，但是他至少能够尝试做一些有帮助的事了。may have done可能已经做了；must have done一定做过某事；should have done应该应经做过某事； would done过去将要做。根据句意故选A。