He is behaving like a subhuman.

He looks down on those weaker than himself as if he despises them.

I found a single fallen leaf in the park.

The company was in turmoil due to his sudden resignation.

He tried to solve the problem all night.

I saw an Old World flycatcher in the park.

In the park, people were playing happily.

No one knows what he did to spend one day.

He feels like a stranger in this town.

Human nature is something that changes.