单选题 16.He______unwisely, but he was at least trying to do something helpful.

【正确答案】 A

【答案解析】本题考查情态动词。may have done表示“某人可能做过某事，但实际上并未做”；must have done表达肯定意味。从句意上看，前者更符合。因此，本题选A。