精选优质文档-倾情为你奉上Unit 1 GREAT SCIENTISTSJOHN SNOW DEFEATS “KING CHOLERA”John Snow was a famous doctor in London so expert, indeed, that he attended Queen Victoria as her personal physician. But he became inspired when he thought about helping ordinary people exposed to cholera. This was the deadly disease of its day. Neither its cause nor its cure was understood. So many thousands of terrified people died every time there was an outbreak. John Snow wanted to face the challenge and solve