1. I think I have a small carbon _________________.
A. amount B. dioxide C. footprint D. energy
2. A wind _________________ turns wind energy into electricity.
A. engine B. turbine C. machine D. fan
3. Solar energy is a clean and _________________ energy source.
A. unlimited B. dangerous C. non-renewable D. limited
4. fuels include oil, coal, and natural gas.
A. Ancient B. Cold C. Fossil D. Frozen
5. Solar power can be used to _________________ or cool our houses.
A. hotter B. heat C. hot D. heating
6. Coal is a _________________ source.
A. non-renewable B. plentiful C. clean D. unlimited
7. In the future, the wind and the sun will be used as the main _________________ energy sources.
A. environmental friendly B. environmentally friendly
C. environmental friend D. environment friendly
8. Those non-renewable sources are going to _________________ soon.
A. exhausted B. lack C. use up D. run out
9. _________________ is a new source of energy available for poor people.
A. Nuclear power B. Biogas C. Gasoline D. Oil
10. Alternative energy sources are _________________, clean, safe, and cheap.
A. abundant B. exhausted C. limited D. expensive