Evolution by natural selection is one of the best substantiated theories in the history of science, supported by evidence from a wide variety of scientific disciplines
False its not particals of air it is some kind of wave. i forget the name of the waves that allow us to hear but it is not particals of air.
In 1775 Jenner began to study the relationship between cowpox (a comparatively harmless disease) and the more dangerous and disfiguring smallpox. ... He hypothesized that exposure to cowpox rendered the body immune from smallpox. After nearly twenty years of experiments, he developed the first vaccine.
It's D. I just took the USA test prep.
