It has been a long time since I learned this but if I remember correctly Pp
Nitrogen is special because it is necessary for growth and reproduction. It's needed for plants and animals to survive. The main function for the atmosphere i believe is to give oxygen and nitrogen.
Acute diseases are sudden, severe, and short term only. They quickly appear and worsen without warning and they disappear. Examples of this are flu or colds.
Chronic diseases, on the other hand, are long-developing diseases. The symptoms have been present for long time and it worsens as time progresses. Examples of this are Osteoporosis and heart disease.
Heart Blood vessels. (Arteries, Capillaries, and Veins)
