Unit 1 GREAT SCIENTISTS JOHN 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 (who were) 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 this problem. He knew that cholera would never be controlled until its cause was found. (expose:1 暴露 be exposed to all kinds of weather.经受风吹雨打。Expose sb to danger 使某人面临危险。 A student who has been exposed to English for some 6 years.接触英语达六年左右的学生。 2.揭露。Expose a politician’s lies. He has been exposed as a liar.他说谎的行为被揭穿。） He became interested in two theories（ that possibly explained how cholera killed people）. The first suggested that cholera multiplied in the air, a cloud of dangerous gas floated around until it found its victims. From the stomach the disease quickly attacked the body and soon the affected person died. John Snow suspected that the second theory was correct but he needed evidence. So when another outbreak hit London （There was another outbreak） in 1854, he was ready to begin his enquiry. As the disease spread quickly through poor neighbourhoods, he began to gather information. In two particular streets, the cholera outbreak was so severe that more than 500 people died in ten days. He was determined to find out why. First he marked on a map the exact places（ where all the dead people have lived）. This gave him a valuable clue about the cause o...
