2018年职称英语综合类B级：阅读文章19

 　　Tipping

　　In any countries there is a fixed charge for personal services. A certain percentage may be added to the hill at a hotel or restaurant "for the service". In other places the customer may be expected to give a tip， or a small amount of money， as a sign of appreciation whenever services are performed. In the United States there is no consistent practice in regard to tipping. The custom is more common in a large city than in a small town. A native American may often be in doubt about when and how much to tip when he is in a city that is strange to him. In general， however， a tip is expected by the porter who carries your baggage， by taxi drivers ， and by those who serve you in hotels and restaurants.