It -------- five years since he left his motherland.

问题描述:

It -------- five years since he left his motherland.
这种句型的题,什么时候用It was,什么时候用It is啊?
具体一点,举个例子啊.....

这里应该用it is相当于it has been
it was用于过去时,时态取决于时间副词的使用