XIV. Điền từ vào chỗ trống “can, must, should, ought” 1. You ............... wash your hand before meals. 2. John is very good at math. He ............ do all math problems. 3. It’s too late. I ............ go now. 4. She gets bad marks at chemistry. She ............ to study harder. 5. The traffic lights are red. You ............... stop. 6. ............... I go to the movies now? 7. Children ............... drink lots of milk. 8. He ............... to drive more carefully.