Diffusion is the movement of molecules from an area where they’re at a higher concentration to areas that have a lower concentration - goo gle
Boys need 2,400 to 3,200 a day, while girls need 1,800 to 2,400 a day.
Hope this helps!
Veins don’t always conduct oxygen poor blood. The pulmonary vein brings reoxygenated blood from the lungs into the heart
I think it's the the colon ??
