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.

Q: airport : train. school : ?

A: bus
****
Q: theater : car. portland : ?

A: car
****
Q: downtown : subway. park : ?

A:
bicycle
****