He is interested in learning the international auxiliary language.

He is interested in paleozoology.

On a summer night, I could hear the cry of the Hachijō cicada.

The International System of Units is a system of units commonly used worldwide.

In order to solve this quantum mechanics problem, we need to find the eigenfunction.

He was immersed in music.

Moderate exercise is good for health.

The police are investigating the source of the threatening letter.

He headed to the mountain with a rucksack on his back.

Cyclops is a part of Greek mythology.