夏日的风可以带来凉意，冬日的风可以吹起漫天的雪花，此外，风还有什么作用呢？
For centuries, farmers have used windmills to pump water, crush grain and perform other tasks. Today, farmers can earn money with high-powered wind turbines that produce electricity. Wind power has become big business, especially in Europe. In the United States, less than one percent of electricity…