什么意思?Many Americans have been leaving their cars at home and riding to work on bicycles. Andy Clark is the executive director of the League of American Bicyclists. His group supports bicycling for fun, fitness and transportation.很多美国人开始把车丢在家里，取而代之骑车去上班。AC是League of American Bicyclists的执行理事，他的公司为人们提供有趣舒适的骑车体验。