A dab of alcohol, a light prick with a needle, and the doctor has ablood sample to examine, almost before you can say,“Ouch, it didn’thurt at all!”Perhaps you have wondered what the doctor cart find outfrom examining a few drops of blood.A blood examination is like a visit to a great river. As you look atthe different kinds of ships sailing up and down, you can tell a great dealabout the country through which the river flows.If you examine the A dab of alcohol, a light prick with a needle, and the doctor has ablood sample to examinees almost before you can say,“Ouch, it didn’thurt at all!”Perhaps you have wondered what the doctor cart find outfrom Examining a few drops of blood.A blood examination is like a visit to a great river. As you look at the different kinds of boots sailing up and down, you can tell a great dealabout the country through which the river flows.If you examine the