Answer:
The valves prevent the backward flow of blood. These valves are actual flaps that are located on each end of the two ventricles (lower chambers of the heart). They act as one-way inlets of blood on one side of a ventricle and one-way outlets of blood on the other side of a ventricle.
Explanation:
This question is poorly stated, but I assume you mean what conditions are needed. It would have to be cold outside, correct?
Answer:
tree frog i believe hope its right
Answer:it’s is part of the cell theory because they where studying cells and to see it you need a microscope
Explanation:basically in the answer area
