听力原文：

G: Luke, how do you get to the subway station every day?

B: I usually ride a shared bike to go there.

G: Can you tell me how to use a shared bike?

B: It’s very easy if you have a smartphone.

G: How should I do it?

B: You have to download an app on your phone and then register.

G: What next?

B: What you do is to find a nearest bike through the app, scan the QR code on the bike, and then enjoy your trip. You can leave it anywhere in public for the next user. You can easily find one and never worry about where to park it.

G: How convenient! No wonder shared bikes have become so popular.

Question: Why are shared bikes popular among people?

参考答案: 

Because they’re convenient.