4. Read these sentences from the article. "Individual layers of ancient sediment form horizontal stripes on the rock. From a few
steps back, the rock wall looks like a cross-section of a giant, stone encyclopedia."
Why might the author have included this description of the rock wall?
A. to explain why the author quotes scientists in the article
B. to demonstrate why the author explains two different methods used to date the rise of
oxygen in the atmosphere
C. to show why the author presents information about different compounds in the article
D. to clarify why the author compares studying a rock formation to studying a book

yes you are doing it right great gob

explanation:

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."