He found her on a dating website.

The Solar System is composed of eight planets, including Earth.

In this experiment, we will use the International System of Units.

He is deeply involved in the study of the meridian system.

We use this coordinate system to locate the position of an object.

The ecosystem of this lake is very fragile.

In physics, the inertial frame of reference is a very important concept.

This system is very complex.

He is an aggressive man in relationships, actively pursuing love.

He is interested in radio wave research.