The circulatory system is system in the human body that provides a network through which our blood flows constantly.The human cardiovascular system is considered closed because there are no holes for blood to enter or leave the system. Correct answer: D
In the closed circulatory system the blood stays confined within the vessels and heart.
Answer:
maybe go for a walk, drink more water, and get some sleep!
Explanation:
Answer:
a, b, c
Explanation:
the last option is explaining a positive effect.
