Two analogies that relate places/locations to the associated travel mode is given in the form "A : B. C : ?". "A : B" relates place A to travel mode B. Your task is to replace the question mark (?) with the appropriate travel mode for the given place C, following the "A : B" relation.

[EX Q]: airport : car. mars : ?
[EX A]: spaceship

[EX Q]: canada : bus. mall : ?
[EX A]: bus

[EX Q]: museum : bus. downtown : ?
[EX A]:
subway

