Exercise 1: Kết hợp câu dùng câu điều kiện 1. He can't go out because he has to study for his exam.  If .......................................................................................................................................................... 2. She is lazy so she can't pass the exam.  If ...................................................................................................................................................... 3. He smokes too much; that's why he can't get rid of his cough.  If ..................................................................................................................................................... 4. I can't play football this afternoon because I felt tired.  If ....................................................................................................................................................... 5. Olga and Ivan weren't paying attention, so they didn't see the sign marking their exit from the highway.  If ...................................................................................................................................................... 6. She can't be employed because she doesn't have a college degree.  If ................................................................................................................................................... 7. She walked to the meeting. She was late.  If .......................................................................................................................................................... 8. Unless you promise to return back, I won't lend you.  If ................................................................................................................................................................ 9. We put off our trip because the weather was terrible.  If .......................................................................................................................................................... 10. Sally doesn't know what she has to do for homework because she was absent from school on Friday.  If ...................................................................................................................................................... 11. If you do not like this one, I'll bring you another.  Unless ........................................................................................................................................... 12. Martin failed his driving test last week because he was very nervous.  But for............................................................................................................................................. 13. He will pay me tonight; I will have enough money to buy a car.  If ................................................................................................................................. 14. Leave me alone or I'll call the police.  If .............................................................................................................................................. 15. If you arrive at the office earlier than I do, please turn on the air-conditioner.  Should....................................................................................................................................................... 16. He died so young; otherwise, he would be a famous musician by now.  Had it ........................................................................................................................................... 17. The car breaks down so often because you don't take good care of it.  Were you ............................................................................................................................................. 18. Don’t tell lies to your boss or you'll be fired at once.  If ..................................................................................................................................................... 19. He didn't revise all his lessons, so he failed the exam.  Had ........................................................................................................................................................... 20. Rita is exhausted today because she didn't get any sleep last night.  If .................................................................................................................................................................