no one could __ failed to notice the fact that ///is a grave problem,这边是用has还是have为什么呢

问题描述:

no one could __ failed to notice the fact that ///is a grave problem,这边是用has还是have
为什么呢

have, could情态动词后面加动词原形,

have
could have +过去分词 - 虚拟语气的固定形式