In crowded places like airports and railway stations you take care of your luggage.A. can

问题补充：

In crowded places like airports and railway stations, you take care of your luggage.

A. can

B. may

C. must

D. will

答案：

A. can

B. may

(答案→)C. must

D. will

解析：句意：在像机场和火车站这种拥挤的地方，你必须保管好你的行李。can能够；may可能，或许；must必须；will将要，表示一般将来时。因此，选C。