2016-2017学年 外研版 选修6 Module1 Small talk Integrating Skills 课件 (10)
2016-2017学年 外研版 选修6 Module1 Small talk  Integrating Skills 课件 (10)第3页

Which of the following is true about the first pair of sentences? A. They both indicate an obligation. B. They are only suggestions about what to do. C. The first one is an obligation, the second one is a suggestion.