It would be probably be 1, as the recommended would be the average
electricity, chemistry, and astronomy
Answer:
Explanation:
1) Excitation brings about contraction.
2) Contraction leads to an increase in blood pressure.
3) Changes in blood pressure results in the opening and closing of the heart valves.
4) The opening and closing of heart valves then regulates the flow of blood and it's volume.
Contraction is the answer
During the first 2-3 weeks you will not see any physical signs. Look at your dog's nipples, for if it is pink, that may be an indication. Be sure to observe your dog's body and it's weight.