Choose the best answer to complete the sentences.
 
1. The park is ______ because many people drop litter on the paths.
 
A. clean B. green C. dirty D. fresh
 
2. ______ the lights when you leave your room is necessary to help save electricity.
 
A. Turning off B. Cleaning up C. Cutting down D. Setting up
 
3. A clean and carbon-free energy mix ensures that their city will remain a healthy and ______ place to live.
 
A. beautiful B. dangerous C. polluted D. harmful
 
4. In one year a mature tree can absorb more than 21 kilograms of ______ from the atmosphere.
 
A. carbon footprint B. carbon dioxide C. gas D. air
 
5. Cars are useful, but their ______ on the environment is another matter altogether.
 
A. protection B. donation C. improvement D. impact
 
6. ______ energy is produced from sources like the sun and wind that never run out.
 
A. Sustainable B. Natural C. Eco-friendly D. Renewable
 
7. We can improve the environment in our school and at home in many ______.
 
A. roads B. ways C. streets D. paths
 
8. Today police launched a campaign to ______ road accidents in the province.
 
A. reduce B. reuse C. renew D. recycle
 
9. Since 1970 the global average ______ has been rising at a rate of 1.7°C per century.
 
A. climate B. warmth C. temperature D. heat
 
10. Petroleum pollution brings a great danger to ocean fishery resource, ______ the natural structure of soil and affects the ecological balance.
 
A. develops B. destroys C. grows D. increases