Which statement is true about nitrogen and oxygen?
a. they make up about 99.9% of the human body
b. they are both used to make water molecules
c. they are both made of protons, neutrons, and electrons.
d. they both contain no subatomic particles

The statement that is true about nitrogen and oxygen is they are both made of protons, neutrons and electrons.  

Explanation:

Nitrogen and oxygen are important for the survival of life. Oxygen is essential to support respiration and energy deriving process of organisms like human beings.

Nitrogen is the element which is essential for healthy growth of plants. Human body is contains oxygen in the highest percentage.  Oxygen content in human body is 65% and Nitrogen content is 3.2%.Thus they would make up only 68.2% of human body and not 99.9% as given in the first option.

Since oxygen and Nitrogen are elements like every element in the universe are made up of sub atomic particles, Proton, neutron and electron .

rocks and weathering-matching

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?