----- Nội dung ảnh ----- 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.