BEFORE TET, THE HOUSEWIVES DO A BIG CLEAN TO GET RID OF THE DIRT OF T...

27.Mexico City, that has a population of over million, is probably the fastest growing city in the world. A. that B. has C. is D. in the world Read and fill in the blanks with the beast answer. We need energy to live and work. Our major source of (28) ____is oil. Oil is one kind of fossil fuel. The amount of fossil fuels in the world is (29) _____. Therefore, we must save it and must find new sources of energy. Geothermal (30) _____and nuclear power are alternative sources of energy. They can give us electricity. Other alternative sources are the sun, waves (31) _____water. These sources are not only unlimited and available (32)_____clean and safe for the environment. People should develop and use them more and more in the future.