has been 加动词原型是什么时态

双语例句：

1、The present regime has been in power for two years.

现政权已经执政两年了。

2、There has been a lot of resistance to this new law.

这项新的法规已经遇到很多的.抵制。

3、She has been to China.

她去过中国。

4、Only time will tell if the treatment has been successful.

只有时间才能证明这种疗法是否成功。

5、The software we use has been modified for us.

我们使用的软件已按我们的需要作过修改。