December 9, 2020

What are modern ships?

A ship is a big boat Ships are designed to travel the ocean. They usually have several decks, or floors, below the water level. Some ships, […]
December 9, 2020

What are submarines?

Submarines are vessels that can travel underwater. They can also float on the surface of the sea and move like any other ship. Many submarines are […]
December 9, 2020

How helicopters work?

The helicopter pilot starts the engine. Its big blades spin-slowly at first, then faster and faster. But the helicopter is still on the ground. The pilot […]
December 9, 2020

How aeroplanes work?

Aeroplanes are usually pushed through the air either by propellers or by jet engines. A propeller looks like two thin, pointed wings joined end to end. […]