be to do结构表示什么意思,与will be结构有何不同,在什么时候使用be to do?

be to do与will be doing be to do.be going to do.be doing.will do.有什么区别? will be doing,be going to do,will do ,有什么差别?be going to leav be going to do结构的用法 be + adj + to + do 语法结构分析! be going to,be doing,will do有什么区别 be apt to do与be inclined to do在英语中有什么区别? be going to do,will be,be doing三种用来表示未来时有什么差别? be doing与be going to do有什么区别? be to do be about to do 有什么区别 be going to和will do和be about to do和be to do和be doing都表示将来,有什 be to do ; will be ; be going to ; be about to ; 现在进行时表将来有什么