1. Quynh was my best friend, but we aren’t friends any more. A. Quynh didn’t use to be my best friend. B. Quynh was used to being my best friend. C. Quynh wasn’t my best friend. D. Quynh used to be my best friend. 2. My parents lived in the USA when they were young. A. My parents used to living in the USA when they were young. B. My parents used to go in the USA when they were young. C. My parents used to live in the USA when they were young. D. My parents didn’t use to live in the USA. 3. We had a nice garden, but now we don’t have any more. A. We used to have a nice garden. B. We used to had a nice garden. C. We used to do a nice garden. D. We used to having a nice garden. 4. She is extremely rich, so she can buy a car. A. She is rich enough to buy a car. B. She was rich enough to buy a car. C. She is poor enough to buy a car. D. She is enough rich to buy a car. 5. Helen couldn’t see any films because she wasn’t free. A. Helen was free enough to see any films. B. Helen isn’t free enough to see any films. C. Helen was busy enough to see any films. D. Helen wasn’t free enough to see any films. 6. I admire the ______________________ use of color in her paintings. A. effect B. effectively C. effective D. affect 7. If we keep _________the air, many people will suffer the serious diseases. A. pollution B. polluting C. polluted D. pollutant 8. What should we do to ________________ pollution ? A. reduce B. reducing C. reduction D. reduces 9. ______________ is a change in weather and how hot or cold it is on Earth. A. Wildlife B. Pollution C. Weather change D. Climate change 10. People should send their trash to ___________________. A. school B. construction site C. landfill D. habitat