Earth is approximately spherical in shape like all planets and stars. Earth is composed mostly of rock. Three-fourths of its surface is covered by a relatively thin layer of water (some of it frozen), and the entire planet is surrounded by a relatively thin blanket of air.
Answer:
Incidence
Explanation:
Isaac will need to assess the incidence rate of HIV-infected adolescents for his research. This must be done because Isaac's research wants to gauge the speed with which this virus is spreading among teens. For this, Isaac must make a comparison between the existing number of patients who fit this case, with patients who fit the recent cases of incidence of the disease. That is, when conducting his research, he will want to examine the number of new cases, the incidence of the disease.
In the lungs, oxygen is put into the blood and carbon dioxide is taken out of the blood during the process of breathing. After the blood gets oxygen in the lungs, it is called oxygen-rich blood.
