1. If people solve the problem of smoke from vehicles and factories, the air _____ pure and fresh. A. is B. was C. will be D. would be 2. If you post false information on the Internet, you _____fined. A. gets B. got C. would get D. will get 3. I believe that if all the people _____ the government’s instructions, we ____COVID-19 from spreading. A. don’t follow/ will prevent B. followed/ will prevent C. follow/ would prevent D. follow/ will prevent 4. Do you think there would be less conflict in the world if all people _____ the same language? A. spoke B. speak C. had spoken D. will speak 5. If our schools are still closed because of the pandemic, we _____to study online. A. wouldn’t B. would try C. tried D. will try 6. If I ____you, I ____many subjects online instead of playing video games. A. was/ will study B. am/ will study C. were/ would study D. am/ would study 7. If people need more paper, more trees _____. A. will cut down B. cut down C. will be cut down D. are cutting down 8. My English is not good. If I ___ English well, I ___ able to get a good job in a foreign company. A. speak/ can be B. spoke / were C. speak/ were D. spoke/ would be 9. If everybody _____to the fight against COVID-19, we will win soon. A. contribute B. contributes C. are contributing D. is contributed 10. If people protect the forest, a lot of trees _____. A. will be preserved B. will preserve C. preserve D. would preserve 11. If you were me, what _____? A. you would do B. will you do C. do you do D. would you do 12. People don’t trust him because he tells lies. A. If he tells lies, people won’t trust him. B. If he didn’t tell lies, people would trust him. C. If he doesn’t tell lies, people will trust him. D. If he told lies, people wouldn’t trust him. 13. The government limits travel and close contact among people, so we can prevent COVID-19 from spreading. A. If the government didn’t limit travel and close contact among people, we couldn’t prevent COVID-19 from spreading. B. If the government doesn’t limit travel and close contact among people, we can prevent COVID-19 from spreading. C.If the government doesn’t limit travel and close contact among people, we could prevent COVID-19 from spreading. D. If the government limited travel and close contact among people, we couldn’t prevent COVID-19 from spreading. 14. Wear a face mask when you are with many people, or you will be at risk. A. If you wear a face mask when you are with many people, you will be at risk. B. If you don’t wear a face mask when you are with many people, you will be at risk. C. If you didn’t wear a face mask when you are with many people, you would be at risk. D. If you don’t wear a face mask when you are with many people, you would be at risk. 18. We/ should/ maintain/ personal space/ avoid/ crowds/ if/ we/ want/ be/ safe/ now. A. We should be maintained personal space and avoid crowds if we want to be safe now. B. We should maintain personal space and avoid crowds if we want to be safe now. C. We should maintain personal space and avoid crowds if we wanted to be safe now. D. We should maintain personal space to avoid crowds if we want be safe now. 19. Her English/ not/ be/ rusty/ she/ used/ more often. A. Her English wouldn’t be rusty if she uses it more often. B. Her English wouldn’t be rusty if she has used it more often. C. Her English wouldn’t be rusty if she is using it more often. D. Her English wouldn’t be rusty if she used it more often. 20. If people/ solve/ problem/ smoke from vehicles, the air/ be pure and fresh. A. If people solved the problem of smoke from vehicles, the air is pure and fresh. B. If people solve the problem of smoke from vehicles, the air was pure and fresh. C. If people solve the problem of smoke from vehicles, the air will be pure and fresh. D. If people solve the problem of smoke from vehicles, the air would be pure and fresh.