I just looked it up, it's carbon!
Codominance means that neither allele can mask the expression of the other allele. An example in humans would be the ABO blood group, where alleles A and alleles B are both expressed. So if an individual inherits allele A from their mother and allele B from their father, they have blood type AB.
Answer: The Pulmonary Arteries
Explanation: They are two pulmonary arteries with on serving each human lungs, which brings deoxygenated blood to the lungs from the hilium. The arteries go into the capillaries of the alveoli. Capillaries are the thinnest ,smallest blood vessel,they supply oxygen to single tissues in all parts of the human body.
You should move this question to Mathematics instead. Or at least physics.
