Antigens are the substances .
It is determined by the presence of absence of antigens A and B on the surfaces of RBCs .
Answer:
Tobacco
Explanation:
Various investigations have identified more than 4000 chemical elements in tobacco smoke particles. It has been shown that at least 60 of them, such as nickel, are carcinogenic. Nicotine, the addictive ingredient in tobacco, stimulates the nervous system, which speeds up the heart rate and increases blood pressure. Other research showed that nicotine stimulates a group of neurons in a region of the brain called the hypothalamus, which are responsible for communicating to the body that it has already eaten enough and is satisfied. Finally, smokers also have other visual effects such as yellowish pigmentation around the fingers, hands, teeth and even the hair can acquire that yellowish hue.
<span>As people who are living in the same planet, it is important that we interact with one another and build a strong relationship because no one lives entirely independently of the others. From the choices, the obstacle in developing good relations is (b) people fear of taking risks. </span>
It would all of the above. As you need all of them for a healthy body.
