Multiple star systems are fascinating to study.

Many invertebrates have open circulatory systems.

The public address systems in the stadium were loud and clear.

Real number systems provide a framework for representing and manipulating numbers.

The renin-angiotensin systems play a crucial role in regulating blood pressure.

The shadow banking systems play a significant role in the global financial market.

Satellite navigation systems are widely used for precise positioning and navigation.

Three-party systems are common in many democratic countries.

Triple star systems are fascinating astronomical phenomena.

The Westminster parliamentary systems are prevalent in many countries around the world.