That would be the nervous system.
Answer:
D
Explanation:
An oil boom helps contain the oil so that it is easier for them to skim it off of the water. They aren't meant to clean up oil, only to contain the oil since it does not sink or mix with water.
The fossils that provide information on the formation of an oxygen-rich atmosphere are the stromatilites from the Precambrian era. These are layered and columnar fossils consisting mainly of cyanobacteria which were the original life form back then. These bacteria took in carbon dioxide and produced oxygen by photosynthesis as early as 2.5 billion years ago (the earth is about 4.5 billion yrs old).
