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

This system is very complex.

I am very interested in marine biology.

Paleoecology is a field of study that investigates the relationship between past organisms and their environment.

He is an expert in paleoecology, pouring his passion into studying past ecosystems.

She started doing yoga to balance her autonomic nervous system.

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

The central nervous system is responsible for transmitting information and controlling the body.

Moderate exercise and a balanced diet are important for maintaining the health of the respiratory system.

He decided to start a manual labor job.