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.

park : bicycle. airport : ?
train

store : car. theater : ?
car

airport : car. australia : ?

airplane