You are learning the shanghai metro: you will read the scene it happens in, learn 10 words and phrases, take apart the pattern behind them (metro navigation vocabulary), hear them in a conversation, rehearse them, and finish by saying one thing out loud to be graded.
Shanghai Metro has 20 lines, 508 stations, and carries 13 million daily riders. It is the longest metro network in the world. Three Chinese phrases navigate all of it.
Shanghai Metro Line 2 is the east-west spine of the city — from Pudong International Airport in the east through People's Square, through Jing'an, to Hongqiao Airport in the west. One line, the whole city.
The stranger needs to get from People's Square (人民广场) to the French Concession area (衡山路). He approaches the info booth. 「去衡山路怎么走？坐几号线？」
The attendant thinks. 「坐1号线，在徐家汇下车，走路差不多十分钟。或者坐10号线，在交通大学站下车，更近一点。」
He chooses Line 10. 「在哪里换乘10号线？」 — 「就在人民广场，同一个站里面换。」 Same station, different platform.
He follows the signs. Three stops. 「在交通大学站下车。」 He reminds himself. The doors open. He exits at Exit 1 and walks toward the plane trees.