A. <span>Exposure to an antigen
Exposure to viruses and antigens led to the foundation of modern vaccination. Vaccination introduces an antigenic material that helps the ability of the immune system to adapt a specific pathogen, therefore leading to a long-term immunity.</span>
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clastic sedimentary rock are made up of pieces of pre-existing rocks. pieces of rock are loosened by weathering, then transported to some basin or depression where sediment is trapped. if the sediment is very deeply, it becomes compacted and cemented, forming sedimentary rock.
Explanation:
Hope this helped Mark BRAINLEST!!!!
Answer:
The black and yellow bird population would begin to starve and would be forced to find alternative food, or die off. This would then send ripples through the food web, causing almost every species to be effected by the grasshoppers being gone.
Answer:
the answer is cirvical cancer.
