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:
Principles
Explanation:
"Specificity and progression" are two principles related to maintaining physical health. Therefore we can say that the word "principles" is the most suitable to replace the word "thing".
Also, "Specificity and progression" are neither exercises nor muscles. Nor are they acronyms, since an acronym is the word formed by joining letters or initial syllables of a group of words, pronounced as one word.
It should be longer but the deepness is fine
C. listening to a patient
