情态动词should与ought to — 英语词汇题
题目
用 should 或 ought to 的适当形式完成句子。1. You o____ to say 'please' when you ask for help.（首字母补全）2. Students ________ (ought to / should — 任选其一填入) keep quiet in the library. 3. We ________ (not ought to) talk loudly on the bus.