ExercisesContentsDownloadsUNIT 20: HAVE TO, DON'T HAVE TO, MUST, MUSTN'TQuestion 1 / 20请完成全部题目,最后查看答案与解析GRAMMAR · A2 Exercise 1 · Exercise 1Choose the correct answer.You _____ apologise; it isn't necessary.Adon't have toBmustn't保存并进入下一题 →