I.        Choose the best one (A, B, C or D) to complete the sentence or replace the underlined word.
1.                 At this time next week we                  to work to support the air pollution cutting down campaign.
A.    are cycling              B. will be cycling        C. will cycle                D. will be cycled
 
2.                 Someone’s carbon                    is a measurement of the amount of carbon dioxide that their activities produce.
A.    footprint                 B. energy                     C. effect                      D. amount
3.                 Remember to               the lights before going to bed.
A.    turn on                    B. stop                         C. turn                         D. turn off
4.                 We will cut down in the use of natural gas because it is                     and harmful to the environment.
A.    available                 B. abundant                C. plenty                     D. limited
5.                 Hydro power is            because dams cannot be built in certain areas.
A.    abundant                B. enough                    C. limited                    D. unlimited
6.                              source of energy is the source that can’t be replaced after use.
A.    Effective                B. Non-renewable       C. Renewable              D. Natural
7.                 Which of the following is NOT renewable source of energy?
A.    wind                       B. coal                         C. hydro                      D. solar
8.                 We are looking for cheap, clean and               sources of energy.
A.    serious                    B. dangerous               C. effective                 D. efficient
9.                 By the middle of the 21st century, people in developing countries                more renewable energy.
A.    used                        B. have used               C. uses                         D. will be using
10.            If we go on                  electricity, we will have to pay a lot next month.
A.    turning on B. widened                               C. wasting                   D. increasing
11.            Biogas is                      and cheap for cooking and heating.
A.    serious                    B. expensive                C. plenty                     D. abundant
12.            We should put             on our roof for the heating and hot water.
A.    equipment               B. cracks                     C. solar energy            D. solar panels