Task 4: Điền vào mỗi chỗ trống sau bằng một động từ khuyết thiếu đã học.
1. I left my bike here and now it's gone. Someone ________ have borrowed it.
2. "The door was open." "It ________ have been open. I had looked it myself and the key was in my pocket."
3. I want this letter typed, but you ________ do it today. Tomorrow you will do.
4. We ________ forget to shut the gates.
5. If you go to a dentist with a private practice, you ________ pay him quite a lot of money.
6. You ________ talk to other candidates during the exam.
7. "Have you seen John?" "No. But he ________ be studying in the library".
8. As I won't be at home tonight, I ________ do my homework during my lunch break.
9. Passengers ________ smoke until the signs have been switched off.
10. There are a lot of tickets left, so you ________ pay for the tickets in advance.
11. I ________ have worn my best suit to the party yesterday; everyone else was very casually
dressed.
12. "What are you doing this weekend?" "I haven’t decided yet. I ________ go on a picnic with my family."
13. Can you repair my bicycle? -Oh, yes, I ________ do it now.
14. It's a secret. You ________ let anyone know about it.
15. I'm not sure. I ________ come a few minutes late.
16. Secondary school students nowadays ________ wear uniform.
17. I had read the book last night before I went to bed. 1 never took it out of this room. It ________be lying around here somewhere. Where ________ it be?
18. When you have a small child in the house, you ________ leave small objects lying around. Such objects ________ be swallowed, causing serious injury or even death.
19. You ________ take your umbrella along with you today. It ________ rain later on this afternoon.
20. I ________ be at the meeting by 10 pm I will probably ________ take a taxi if I want to be on time
