has+动词过去式是什么时态

has+动词过去式是一般过去时态。

has有;have 的第三人称单数现在时形式。

A new system has been devised to control traffic in the city.

控制城市交通的\'新系统已经设计出来。

The company has a long tradition of fine design.

这家公司的优秀设计历史悠久。

The country has a poor record on human rights.

这个国家人权记录不佳。

The information has been placed in the public domain.

这资料不受版权保护。

He has carried out extensive research into renewable energy sources.

他已经对再生能源进行了广泛研究。