The major organ of the circulatory system that causes blood to flow through the body by its pumping action is the heart.
<span>External circumferential lamellae</span>
The answer has to be option B "testable." A hypothesis is a educated guess on what you think is going to happen during a experiment. Also its not going to be option A because a hypothesis doesn't exactly have to be written homeschool students have there instructions on a computer in order to be completed. Its not option C because a hypothesis has the have its test variables. (independent & dependent variables) Its also not option D because some scientists conduct their experiments by themselves.
Hope this helps!
<span>Sedatives, Barbiturates and Tranquilizers</span>
