hasdone是什么时态

He has done sterling work on the finance committee.

他在财务委员会工作优异。

As far as I'm aware , nobody has done anything about it.

据我所知，尚无人对此采取任何措施。

His equivocal response has done nothing to dampen the speculation.

他模棱两可的`回应丝毫没有减弱人们的猜测。