... are many communities doing to produce electricity? A Burning garbage and other boilogical waste B Changing waste products into gases or oil C Doing experimental woek C Making synthetic fuels 47 ... hydroelectric power which is derived from stream and rivers Fifty years ago, hydroelectric power provided one-third of the electricity used in the United States, but today it supplies only four per...
Ngày tải lên: 23/07/2014, 06:20