How is air useful to:

(a) water boats

(b) agriculture

(c) windmills

(d) scooters and cars?

(a) Air helps in the movement of water boats by providing air resistance.

(b) Air speeds up drying up of wet agricultural products like grains, pulses, fruits and air helps in pollination of flowers and dispersal of seeds.

(c) Windmills move due to the movement of air. They are also used to generate electricity.

(d) Air is filled in tyres of vehicles like cars, scooters, trucks, buses, bicycles, etc. for their smooth movement.