1. The wind, the sun, and the wave are some types of __________ sources of energy. A. changeable B. alternative C. cheap D. costly 2. Remember to __________ the lights before going to bed. A. turn B. turn on C. turn off D. stop 3. People will reduce energy __________ as much as possible. A. consume B. consumption C. expense D. expenses 4. Nuclear power is expensive and dangerous __________ our environment. A. for B. to C. in D. with 5. Human is looking for a clean, cheap and __________ sources of energy. A. effective B. effect C. effectively D. effectiveness 6. Low energy light bulbs should be used to __________ electricity. A. spend B. buy C. convert D. save 7. We must __________ the amount of water our family used every day. A. lower B. reduce C. lessen D. narrow 8. At this time next month we __________ to Ha Long Bay for a holiday. A. will go B. will going C. will be gone D. will be going 9. By the middle of the 21st century, people in developing countries __________ more renewable energy. A. uses B. will be using C. used D. have 10. Fossil fuels are very common in our society but they __________ the environment. A. renew B. provide C. waste D. pollute