Circulatory systems ____.
A) are found in all animals
B) result in slow distribution of nutrients and gases
C) include one or more hearts
D) are always closed systems
E) are found in cnidarians and flatworms

Question

Circulatory systems ____.​
A) are found in all animals​
B) ​result in slow distribution of nutrients and gases
C) ​include one or more hearts
D) ​are always closed systems
E) ​are found in cnidarians and flatworms

Quizplus · Accepted Answer

Circulatory systems often include one or more hearts to pump blood or hemolymph through the body.

Circulatory Systems ____.​

Circulatory Systems ____.