有will be finished doing这种用法么?

be going to doing这种用法有吗? be just doing sth 有这种用法吗 be sth terrified of doing有没有这种用法 sb be seen doing 有这种用法吗? notice sth/sb be doing 这种用法有吗? 请问有没有need to be doing sth这种用法 be finished doing这个问题 关于will be doing的用法 will be doing 是种什么用法? decide on doing sth 有这种用法么 have no mean in doing sth有这种用法么? be going to be,will be和be doing在用法上有什么区别,什么时候用什么