There are seven crystal systems in mineralogy.

The drainage systems in this city are well-maintained.

The endocrine systems regulate various physiological processes in the body.

There are various ethical systems that people follow.

Feudal systems were prevalent in medieval Europe.

The office has multiple filing systems to organize documents.

Formal systems are widely used in computer science and mathematics.

The Ghent systems are widely used in the field of data analysis.

The exhaust systems of these cars are very efficient.

The haversian systems are responsible for the structural integrity of bones.