After she swipes her monthly pass, she can walk through the turnstile. 她刷了月卡，就能穿过十字转门。

The turnstile, "turnstile," (one word) is a machine that prevents you from walking through somewhere. 旋转门(turnstile)是一种机器，它可以阻止你穿过某个地方。

It has a bar and after you pay, you can then push the bar and the bar will move forward - the bar is just a piece of metal, 它有一根栏杆，付钱之后，你可以推动栏杆，栏杆会向前移动——栏杆只是一块金属，

and then, the next person has to pay and they can push through with the turnstile. 然后，下一个人必须付钱，才可以通过旋转门。

One person goes through at a time, and you'll find turnstiles at subway stations, sometimes at train stations. 每次只能通过一个人，你会在地铁站看到十字转门，有时在火车站也有。

If you don't have any money, you can just jump over the turnstile. 如果你没有钱，你可以跳过十字转门。

I would not recommend that, however, because they might arrest you if you don't pay! 但是，我不建议你这样做，因为如果你不付钱，你可能会被抓起来!

Lucy says she waits "on the platform for the first express train." 露西说她“在站台上等第一辆特快列车”。

The platform, "platform," (one word) is the place where you wait for the train or the subway to stop, and then the doors open and you walk onto the train. 站台(platform)是等火车或地铁的地方，火车或者地铁会在这里停下，然后门开了，你走到火车上。

The platform is the place where you wait right next to the tracks, "tracks." The tracks are what the trains go on. 站台是你在轨道(tracks)旁等着的地方。火车沿着轨道走。