The heart is the main organ of the circulatory system.
The Heart is the main organ of a circulatory system.
the heart is part of the circulatory system in the body.
The main organ of the circulatory system is the heart.
the heart is the main circulatory organ of the frog
The circulatory system and the cardiovascular system. :D NOT jk
Circulatory.
respitory, digestive, and circulatory =
The one that controls circulatory is the heart
Circulatory
LUNGSSS
The Cardiovascular system
Circulatory.