Step-by-step explanation:
Sir Isaac Newton's third law of motion says that every action has an equal and opposite reaction.
For example, when you fire a gun, the gun exerts a force on bullet. Even the bullet exerts an equal force on the gun, causing it to recoil.
The Earth revolves around the Sun as the Sun attracts it. The reason why Earth doesn't fall into it is because the Earth also attracts the Sun with an equal gravitational force.