have been done 与 having been done 与have been doing与having been doing有什么区别
问题描述:
have been done 与 having been done 与have been doing与having been doing有什么区别
答
have been done
已被做完
having been done
是上面的现在分词短语.
have been doing
在过去动作开始一直在进行着.
having been doing
是上面的现在分词短语.
明了吧.