徐然推理小说百度云:Coffee ought to be drunk while it is hot

Coffee ought to be drunk while it is hot 讲讲ought to的用法 It ought to be you rather than me that signs the letter.这里的signs的用的对吗？ ought是什么意思啊？ought to呢？有什么用途？ 用should，ought to，have to填空 ought to与should有何区别？ You ought to wear warmer clothes. ought to 和 may 有什么区别 I ought to fogot somthing with you ought to和should有什么区别？