33.many countries are using solar energy
34.at present,most of our electricity comes from the use(of) coal,gas...
35.turn off all the lights every time you leave (the) room
36.one percent of solar energy reaches to the earth is enough to provide the power for the total population
37.fossil fuels won't be burned for energy in the future
38.bạn đúng r
39.will our electricity bills be reduce....
40.in the countryside,people will burn plants to produce heat
