Answer: "oasis" .
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Bacteria are required or needed in the nitrogen cycle because other living properties cannot use atmospheric nitrogen.
<h3>What is the nitrogen cycle?</h3>
The nitrogen cycle is the sequence of operations by which nitrogen and its mixtures are interconverted in the environment.
In living organisms, It considers nitrogen fixation and pollution.
As regards Nitrogen fixation is affected, just bacteria are competent to improve atmospheric nitrogen into structures usable by other living organisms.
In nitrogen fixation, the atomic nitrogen is converted into chemical forms functional by plants and convert atmospheric nitrogen into chemical forms functional by plants.
Therefore, option A is correct.
Learn more about the nitrogen cycle, refer to:
brainly.com/question/9243222
Fertility rates and resources are connected because in areas where there are scarce resources and high fertility rates there will be problems in the ability to provide for the members of this hypothetical society. Therefore, individuals or animals could potentially live shorter and less healthy lives because of the lack of proper resources such as food, water, healthcare, or education.
Reason a is the correct one, as the european union has nothing to do with protection from invasions and Germany reunified many years ago.