今天我们要学的词是maintenance. Maintenance 维修，养护。The U.S. Interior Department will hike fees at the most popular national parks to $35 a vehicle to raise funds for park maintenance. 美国内政部宣布，全美游客最多的国家公园每辆车进园的门票将升至35美元，筹集资金用于公园养护。A new report says that nearly a quarter of heavy U.S. aircraft maintenance is performed offshore, up from 7% in 2003. 一份最新报告称，美国飞机大型维修近四分之一都是在海外进行的，在2003年7%的基础上大幅度上涨。好的，我们今天学习的词是maintenance, maintenance, maintenance ...