open
OPEN
The light bulb is a closed system: no mass transfer.
Closed System
Amphibians have closed circulatory system Closed
closed circulatory system
A battery-operated wrist watch is a closed system. A wind-up wrist watch is an open system.
closed
Closed
Closed
closed!
Is the stratification system of south africa closed open or mixed
Frogs have a double circulatory system, which means that circulation goes from the heart to the lungs (where it becomes oxygenated), then returns to the heart, then is pumped to the rest of the body (which takes the oxygen), and then returns to the heart. They have a closed circulatory system, which means that the blood travels through the body in vessels. Frogs have a three-chambered heart.