hasdone是什么時態(tài)

　　He has done sterling work on the finance committee.

　　他在財務委員會工作優(yōu)異。

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

　　據我所知，尚無人對此采取任何措施。

　　His equivocal response has done nothing to dampen the speculation.

　　他模棱兩可的回應絲毫沒有減弱人們的猜測。