He was the main character of the scene.

I like watching children play in the park.

He always lives without forgetting his child's naive mind.

In physics, momentum is defined as the product of the mass and velocity of an object.

If the motor nerves are damaged, you will lose control of your muscle movements.

He is bad at athletics, especially ball games.

He participated in the student movement of the 1960s.

A sports festival will be held at school next week.

Kinetic energy is directly related to the speed of an object.

He is a famous athlete.