How clean the bedroom is!Yes,I amsure that someone___it.

问题描述:

How clean the bedroom is!Yes,I amsure that someone___it.
A.cleans B.cleaned C.has cleaned D.is cleaning

选C啊.
现在完成时特别强调对现在有影响.
过去式就语气稍微浅一些.
两个时态最大区别就是一个强调动作发生在过去,
一个强调过去动作对现在造成影响或结果.