200
_______ is made of 4 main things:
1.plasma-pale yellow, mostly water, carries food, minerals and homones.
2.red blood cells-carry oxygen, single drop contains 200 milloion red blood cells.
3.white blood cells-kills bacteria, attaching themselvs to bacteria, smothering it and eating it.
4.platelets- stops bleeding, when their is a cut, stringy fibers form over the hole.
What is blood?