It is intended to increase immunity against that antigen back to protective levels, after memory against that antigen has declined through time.
Answer:
S phase is the correct answer. Hope this helps...
Explanation:
Increasing levels of chemicals in freshwater is attributed to fertilizers because in agriculture most of the farmers use fertilisers for a better crop, but those chemical fertilisers eventually flow into the water bodies and gets mixed with them. Therefore harming it and being an attribute.
Answer:
Option A is the answer.
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