Answer:
I know you only need two, but here:
--Subsidence and sinkholes.
--Sinkholes and caverns.
--Waterfalls and rapids.
--Deltas and levees.
--Erosion and abrasion.
Explanation:
The two gasses that make up 99% of the earth's atmosphere are nitrogen and oxygen.
Hope that helped! =)
I think that the answer is C- "I RNA contains uracil and ribose." because it is the one that mostly makes sense and is the one that most shows the difference between RNA from DNA.
According to google: "Ribonucleic acid (RNA) is a polymeric molecule implicated in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the three major macromolecules essential for all known forms of life."
I hope this helped!