Classify the below based on the mode of transportation.
bus, car, taxi, train, helicopter, boat, ship
Travel by land- bus, car, taxi, train
Travel by water- boat, ship
Travel by air- helicopter
Instruction: Classify the below based on the mode of transportation.
bus, car, taxi, train, helicopter, boat, ship
Context: 
Response: Travel by land- bus, car, taxi, train
Travel by water- boat, ship
Travel by air- helicopter