to be doing和to have done为什么不能作状语

to be doing和to have done为什么不能作状语 怎么区分谓语动词,to do doing done 和to be doing to be done to have do 请问不定式和having done 还有to have done 是不是不能做伴随状语? to be doing为什么不能非谓语动词作主语 being done 和 be doing ;done ；doing ; be done ;to be done 的用法 为什么有doing=to be done have been done 和 to be done need doing 和need to be done Be said to do和be said to be doing和be said to have done有什么区别 to do / to be doing / to have done / to have been doing/doin to be done to have been done to have been doing 形式的造句, to have done 目的状语