单句改错:it is pretty well understood how control the flow of carbon dioxide答案是how→what请问为什么是这个答案?how后面加to,请详细说明.

问题描述:

单句改错:it is pretty well understood how control the flow of carbon dioxide
答案是how→what
请问为什么是这个答案?how后面加to,请详细说明.

it is pretty well understood what( control the flow of carbon dioxide)
( control the flow of carbon dioxide)作为补足语修饰what