The police strengthened security to prevent unauthorized entry into the building.

He entered my room without permission.

Every year, many fish gather in this river for spawning.

Frogs spawn when spring comes.

Due to overfishing, there is a possibility that the marine ecosystem could be destroyed.

The problem of overfishing is having a serious impact on marine ecosystems.

I plan to go to a new expo this weekend.

My work will be displayed in this museum.

The city was hit by a large-scale riot.

Her face is a beautiful oval shape.