Answer:
D) four.
Explanation:
The two atria hold the blood that circulates away from the heart. The heart has four one-way valves, which open and close with each heartbeat. The tricuspid valve and the mitral valve are located between the atria and allow the blood to flow from the atria to the ventricles. Also you don't have to but mind marking Brainliest?
Maintain friendships with supportive and caring people.
Answer:
The answer would be D. limited results.
Explanation:
You can't get moderate or extreme results when putting in minimal effort.
Muscles make up about 40% of a person's total body weight.