Bicarbonate buffer system. Human blood contains large amounts of carbonic acid, which is a weak acid, and bicarbonates, a strong base. If blood pH falls below 6.8 or rises above 7.8, one can become sick or die. This bicarbonate buffer system help maintain blood pH at 7.4. The bicarbonate neutralizes excess acids in the blood while the carbonic acid neutralizes excess bases.
Assume as what happens in a pot of water as it get heats.. hot becomes less dense, rises and cools, becoming more dense then sinks- that's called CONVECTION
So D- is the right answer
Ice age. It caused saber tooth and mammoth to die
<span>50 percent. Newborn has very low listening ability and learning as brain develops the child will learn new things and his brain starts to grow big .Brain will adapt the language,color ,light,people faces and then child will learn fast</span>