Answer:
the last choice.
Explanation:
veins have valves because venous pressure is often not great enough( as the blood must overcome gravity and other forces) to return the blood to the heart.
valves mainly prevent the back flow of blood.
Definitely No. Just be you.
Answer:
a person’s condition with regard to their psychological and emotional well-being.
Answer:
same, dont worry
but do try to eat something if you can though :)