there has been too much rain in china this year.为什么要用been?

there has been too much rain in china this year.为什么要用been?

这是现在完成时,固定要这么用.语法是：has/have been.由于主语是there所以后面要跟has.

状语是this year， 这是一段时间，要用现在完成时。
there is 要变成 there has been