十万火急what should be done have benn done为什么要将have改为has?

问题描述:

十万火急what should be done have benn done
为什么要将have改为has?

把what should have been done想成是一个词.
"需要做的事情",是个第三人称单数阿.不是第一人称呀,所以后面要改成和第三人称同步的has