zài zhè sìshífēnzhōng lǐ ， tā guānchá chēxiāng lǐ de chéngkè ， fāxiàn dìtiě xiàng yīzuò chéngshì de xiǎo chuāngkǒu 。

在这四十分钟里，她观察车厢里的乘客，发现地铁像一座城市的小窗口。

In those forty minutes she observes the passengers, finding the subway a small window into the city.