He is selecting music for the party.

Writing a declaration is difficult.

The demarcation of this area is clearly defined.

We decided to demarcate this land.

By chance, he met my old friend.

In the early morning, he brewed coffee and started his day.

He completed the project in a week.

I'm always busy during the daytime, and I only have time to rest at night.

He had been working overseas for an extended period of time.

The theory of spacetime is an important part of physics.