These years you can see many underground railways are being built in some big cities. underground railway is both convenient and fast. the underground railway is also called “the subway‘.

　　There‘re lifts for you to go up or down. the trains‘ doors open and close automatically. in shanghai, during rush hours the underground arrives at the station every two minutes.

　　But with too many people taking the underground, people find it really too crowded. maybe shanghai needs more underground railways.
翻譯：

這些年在一些大城市你可以看到許多地下鐵路正在興建。地下鐵路既方便又快速。地下鐵路也被稱為“地鐵”。

這有電梯供你上下。列車門自動打開和關閉。在上海，繁忙時間下每2分鐘就有一列地鐵到達。

但隨著越來越多的人乘地鐵，人們發現它太擁擠。也許上海需要更多的地鐵。