爱华网名词解释： 绿皮车，墨绿色外表，中国铁路客车当中绿色涂装配黄条色带车底的俗称。客车车身通常为绿色底色和黄色色带的涂装。“绿皮车”曾经是中国旅客列车的最具代表性的形象。典型的有22型客车、22B型客车、25B型客车等系列的旅客列车车厢。其中以22型系列客车生产量最大，最具代表性。你知道用英语怎么表达吗
Such so-called "green-skinned" trains (named for the color of their external paint) started running in the 1950s, which are known for their distinctively slow pace and lack of air conditioning, as well as their belching black smoke.
In addition, at times, the cheap, old-fashioned "green trains" were so crowded that with doors blocked, people had to crawl through windows in order to board.
Now, as modern high-speed trains whoosh past new stations throughout China, it's time to say goodbye to the old-time green trains.
Though green trains still run locally in some areas, they are gradually being phased out.
这种被称为“绿皮车”的列车(因其外部油漆是绿色而得名)，它的特点是奇慢的车速，没有空调以及喷出的黑烟。
这种票价低廉的老式绿皮车还时常拥挤不堪，门口被人堵住后，人们上车得从窗户爬进去。
现在，随着现代高速列车飞速驶过全国各地新建的火车站，也到了和旧式的绿皮车告别的时刻了。
虽然绿皮车依然在一些地区运行着，但将被逐渐淘汰。
【讲解】
文中的green train就是“绿皮车”的意思，也可以称为"green-skinned" train，因票价极其便宜而在上世纪颇受欢迎，其中train用作名词，意为“火车，列车”，常见的类型有：slow train(慢车)，special train(专列)，through train(直达列车)等，现在较普遍的“高铁”则是high-speed rail。
最后一段的phase用作动词，意为“逐步执行”，如：The use of lead-free petrol is now being phased in.(正在逐步推广无铅汽油的使用。)
