Exercise 1: Chọn đáp án đúng nhất để điền vào chỗ trống trong mỗi câu sau. 1. Young people ______ obey their parents. A. must B. may C. will D. ought to 2. Laura, you and the kids just have dinner without waiting for me. I ______ work late today. A. can B. have to C. could D. would 3. I ______ be delighted to show you round the factory. A. ought to B. would C. might D. can 4. Leave early so that you ______ miss the bus. A. didnt B. wont C. shouldnt D. mustnt 5. Jennys engagement ring is enormous! It ______ have cost a fortune. A. must B. might C. will D. should 6. You ______ to write them today. A. should B. must C. had D. ought 7. Unless he runs, he______ catch the train. A. will B. mustnt C. wouldnt D. wont 8. When _____you come back home? A. will B. may C. might D. maybe 9. _____you A. may B. must C. will D. could.