8. If you want to go __________ one place to another in this city, take a taxi. A. A B. from C. after D. for 9. Remember to __________ the lights before going to bed. A. turn B.turn off C. turn on D. stop 10. A hydropower station __________ in the North of the country next year. A. was built B. were built C. will be built D.has been built 11. Biogas is __________ and cheap for cooking and heating. A. plenty B.abundant C. serious D.expensive 12. What should we do to __________ electricity? A. cut B.take C.save D.waste 13. We are looking for cheap, clean and __________ sources of energy. A. effective B. efficient C.serious D. dangerous 14. We should put __________ on our roof for the heating and hot water. A. solar energy B. equipment C.cracks D. solar panels 15. Nuclear power __________ in the future. A. will replace B. replace C. will be replaced D. replaces