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.

That man-child is still living in his parents' house.

He is called a 'kid's room uncle', and is alienated from society.

I reserved a single room.

We booked a double room.

She started doing yoga to balance her autonomic nervous system.

He is a person of strong vanity who reads self-improvement books.