which gas is most abundant in earth’s atmosphere?
a.
oxygen
b.
nitrogen
c.
carbon dioxide
d.
methane

Many people try to eliminate fat from their diets. which is one reason it is necessary for humans to eat fat? a. eating fat is the fastest way to get energy. b. fat eliminates triglycerides from the body. c. saturated fats clear out the blood vessels. d. fat nerves transmit signals. , this is for apex in summer school.

Which statement about the immune system is false? a. lymphocytes reduce inflammation, b. b cells remember specific pathogens. c. most white blood cells kill bacteria d. white blood cells are made in lymph nodes.

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.