be going to,be to do,be about to do 有什么区别

be going to do、be about to do、be to do,这三者有什么区别? be to do be about to do 有什么区别 be to do,be going to do,will do,be about to do的区别. be to do.be going to do.be doing.will do.有什么区别? be doing与be going to do有什么区别? be going to,be doing,will do有什么区别 将来时态的区别be going to;will do;be doing;be to do;be about to do be to do ; will be ; be going to ; be about to ; 现在进行时表将来有什么 be to do和be about to do有什么区别? be to do sth.和be about to do sth.有什么区别? be about to do和mean to do和intend to do有什么区别 be to do和be going to do的区别