Answer:
The answer is the Immune system (a).
Explanation:
The immune system consists of agents that help your body fight against pathogens and other invading substances. It has your white blood cells, enzymes, mucus, hydrochloric acid (in your stomach), and even your saliva. All these substances help make sure your body is rid of anything that may bring harm to you!
Answer:
bone density.
Explanation:
I used precess of elimination. U cannot improve the bone density by working out. You can improve your cardiorespiratory fitness by doing cardio, e.g. cycling, swimming, running etc. You can improve muscular strength by working out, e.g. push up, sit ups, etc. you can also become more.flexible by expanding ur muscles and tissues.
Answer:
Explanation:
Cardiopulmonary resuscitation (CPR) acts as a manual heartbeat, keeping vital organs alive even after the heart has stopped beating.
Artificial External Defibrillator (AED) is an electronic device that is used to revive a person's heart when it has stopped beating.