Because they are easier to obtain (i.e. you don't need a script from the doctor to get them, you can go and buy them freely) and in some cases can give you the same high as street and prescription drugs
Blood Provides the Body's Cells with Oxygen and Removes Carbon Dioxide. Blood absorbs oxygen from air in the lungs. It transports the oxygen to cells throughout the body, and it removes waste carbon dioxide from the cells.
Parasites are many types of viruses like bacteria that reproduce on their own
