If a 'truck' is called 'train', 'train' is called 'tractor', 'tractor' is called 'ship', 'ship' is called 'aeroplane', 'aeroplane' is called 'bulldozer' and bulldozer' is called 'scooter' which of the following can fly?
1.Ship
2.Bulldozer
3.Tractor
4.Aeroplane