He-----unwisely,but he was at last trying to dosomething helpful.
问题描述:
He-----unwisely,but he was at last trying to dosomething helpful.
A.should act B.would act C.may have acted D.must have acted
参考答案为C,可是后面的was不是表示过去吗,前面应该是had acted 为什么是have,
答
may have acted 情态动词加完成时态,表对过去的推测 他那时也许做的不明智 was trying过去进行时 something helpful 不定代词形容词做定语后置 整个句子是以but连接的并列句