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Bài 9: Điền động từ khuyết thiếu "must" hoặc "mustn't" vào chỗ trống.

1. You ________ be late.
2. You ________ tidy up your room.
3. I ________ smoke.
4. You ________ be home by 9 o'clock. The film starts at 9:15.
5. We ________ do your homework.
6. Passengers ________ finish this essay today. It has to be handed in by tomorrow.
7. You ________ play with fire.
8. This is a dangerous tour. Children ________ be accompanied by an adult.
9. People ________ stand on this bus.
10. You ________ cheat in a test.
11. You ________ do more exercise to stay fit.
12. There ________ turn the music too loud.
13. There ________ be something wrong with the engine of this car.
14. We ________ help in the house.
15. You ________ give up when we are so close.
16. You ________ annoy your little sister.
17. This was a nice evening. We ________ meet again.
18. You ________ bite nails.