The correct answer is - cyanobacteria.
The atmospheric oxygen came from the cyanobacteria. These were one of the earliest living organisms on Earth. The cyanobacteria was using photosynthesis in order to create its own food. The photosynthesis process requires sunlight, carbon dioxide, water, and oxygen. The oxygen is mostly released as a waste product from the process of photosynthesis, thus the cyanobacteria were literally releasing oxygen that was ending up into the atmosphere. As more and more cyanobacteria there were across the planet, more and more oxygen they were releasing into the atmosphere, slowly changing the composition of the atmosphere, and setting the basis of it as we know it now.
D) He was the head of the Freedmen'd Bureau.
The answer is C because the earth gets hotter as you go deeper into it therefore the continental crust which is the outside would be the coolest. The inner core is the hottest then the outer core then the mantle and then the crust would be the coolest.
Answer:
lowest level of the atmosphere
Explanation:
The reason why its found in the lowest lvl is mainly because 99% of the water vapor in the atmosphere is found in the troposphere(lowest level)
C.)Dry I believe is the best choice here, given that this region is composed primarily of deserts
