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outbreak – n. a sudden start or increase of fighting or disease
sewage – n. wastewater and human waste products
sample – n. a small amount of something that represents what it is like
significant – adj. important or noticeable
dilute – v. to make a liquid thinner or weaker by adding water or another liquid to it
positive – adj. in a medical test, positive means the person being tested has a disease or condition
isolate – v. to put or keep (someone or something) in a place or situation that is separate from others
