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Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
Liver spots have nothing whatsoever to do with the liver. They are a type of freckles commonly seen in older adults who have been out in the sun without sufficient sunscreen.
Warfarin was developed as a consequence of the study of a strange bleeding disorder that suddenly occurred in cattle on the northern prairies of the United States in the early 1900s.
Vaccines cause herd immunity. If the majority of people in a community have been vaccinated against a disease, an unvaccinated person is less likely to get the disease since others are less likely to become sick from it and spread the disease.