Answer: A
Explanation: Vaccines create memory cells with a weak version of the pathogen, so when they meet that pathogen again the body can respond more quickly and more efficiently since they have already been exposed to the pathogen.
Answer:
google said deep and haw rivers
Answer:
The Peppered Moth is widespread in Britain and Ireland and frequently found in ordinary back gardens, yet its amazing story has made it famous all over the world. It is one of the best known examples of evolution by natural selection,
Explanation:
The purpose of scientific notation is to demonstrate very large or very small numbers, this is what it looks like, 7800000000000 in scientific notation would be 7.8*

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