He knows my secret, so he has something on me.

Democracy is a political system that runs the country according to the will of the people.

There are various ethnic groups in the world.

He is very interested in science.

I think it's important to get enough sleep.

The wolf lives alone in the forest.

I'm sleepy, so I'll go to bed early.

He practices every day to polish his skills.

He visited his grandfather's gravestone and prayed.

He kept running without looking back at the road.