Blood circulation in a mammalian is said to be double because
it passes twice through the heart in a complete circuit
it moves in both arteries and veins
it circulates in both the heart and other organs
the heart contain auricles and ventricles
The correct answer is: A
Explanation
No official explanation is available for this question at this time. Please check contributions posted by others below. If you can provide an explanation to help other student learn.