Explanation:
Each hemoglobin molecule is made up of four heme groups surrounding a globin group, forming a tetrahedral structure. ... There are four iron atoms in each molecule of hemoglobin, which accordingly can bind four atoms of oxygen. Globin consists of two linked pairs of polypeptide chains.
The answer is D. A person can get an STI from oral sex. Oral sex is one of the most common ways to contract an STI.
Answer:i would say skinner
Explanation: look at the skinner's theory