Experts say that sun and wind are the richest sources of clean, renewable energy. But ocean waves also create powerful, clean energy. So, the U.S Department of Energy has announced a $1.5 million-dollar prize for the winner of a competition on how to capture that energy._______________________专家认为,太阳和风能源是最富有的清洁和可再生能源.然而海浪也可以创造动力,清洁能源.所以,美国能源部宣布,将拨款150万美元奖励给能够掌控这股能源力量的人.________________________
