第21题: [单项选择]{{B}}Questions 11 to 18 are based on the conversation you have just heard.{{/B}} A. They ought to make fresh coffee. B. They ought to try some other kinds of coffee. C. The machine should be cleaned. D. The machine should be replaced. 参考答案:D 答案解析:[听力原文]
W:we ought to stop buying this kind of coffee.It always tastes terrible.
M:Maybe we should