It increases with distance from the ocean ridges.
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.
Answer:
Option (A)
Explanation:
In the above-given question,
Option (B) is wrong with it's usage of the modifier "how'' in the sentence. If the modifier is used in one place (how heat from the inner core flows), it should also be used in the continuing clause (how the formation and periodic reversal).
Options (C) and (D) are wrong in using the word "are" for the whole sentence as there is no need to use this word. The verb form will depend on the subject, in this case, is "the discovery that earth's inner core" which is singular in nature. Thus, the verb form will be -is and not -are.
Option (E) is wrong for it's use of the comma. If the comma is used, then the whole sentence is not a full-fledged sentence but rather a dependent clause with no resolution.
The correct answer for the given passage is option (A).
The Ural and Caucasus mountain Ranges
The river is used as a major source of drinking water for Savannah and Augusta, to cool nuclear power plants in Georgia and South Carolina, and to generate hydroelectric power. Other uses include irrigation for agricultural crops and recreation.
