"chọn câu đúng và giải tại sao chọn câu đó(câu đó có đặc điểm gì để chọn)" 21. You look so tired. You ....... go to bed early. A. will B. must C. should D. would 22. Walking home alone is not a good idea. => You A. can't walk home alone. B. mustn't walk home alone. C. don't have to walk home alone. D. shouldn't walk home alone. 23. I really think you.....go and see the doctor, you look very tired. A. would B. should C. will D. need 24. You've been coughing a lot lately. You smoke so much. A. shouldn't B. can't C. should D. can 25. I don't think you work so hard. You're not very well. A. would B. need C. should D. must