There are too many difficulties for us to deal with.We really don't know ________ to do.(Unit6-5)为什么用what不用how?请分析一下句型或语法.

问题描述:

There are too many difficulties for us to deal with.We really don't know ________ to do.(Unit6-5)
为什么用what不用how?请分析一下句型或语法.

怎么做在英文里用 how to do .不用 what to do
虽然翻译成中文好像都可以用。

how to do 后面要加宾语的