It is pretty well understood____controls the flow of carbon dioxide in and out the atmosphere填what,但是请告诉我这是主语从句还是宾语从句?若是主语从句,那么,what引导的主语从句不是不能用it作形式主语的?
问题描述：
It is pretty well understood____controls the flow of carbon dioxide in and out the atmosphere
填what,但是请告诉我这是主语从句还是宾语从句?若是主语从句,那么,what引导的主语从句不是不能用it作形式主语的?
答