be to 和be about to 有什么区别,用法个是什么.

e to do 表示“按计划要做某事,事先安排好的,有一定的目的性” 如：I am to attend the meeting. be about to 表示“将要,暗含的意思是立刻,马上” 如：I must be about to make a decision because it is important. be going是现在进行时表示将来时,动词通常是移动性的词,如：move ,leave等 如：I am going to the city tomorrow.
希望采纳