e supposed to do是被期望或要求,应该.相对于be expected to do 主观性强一些.它相当于should的这个用法
是有希望做(成)……
expect在朗文的第一词条即为:预料、期待.
例:They are expected to make an announcement later on today.(预料他们今天晚些时候会宣布一项通告)
再次例句中,be expected to do意为预料,表示一种可能性
再如:She is expected to be a good doctor.(他有希望成为一名好医生)