Microwaves and radio waves are employed in radio and satellite communications while infrared waves are used in remote controls and infrared features of new phones and other electrons. However, gamma rays have far too much energy and cause damage to the body. They are not used in communication.
The answer is A.
Divide
(the distance covered in some period of time)
by
(the time taken to cover the distance).
The quotient is the average speed during that period of time.
Reactants
In a chemical reaction, the substances that undergo change are called reactants. The new substances formed as a result of that change are called products.
Gravity is the energy due to Earth pulling down on an object.