北京外国语大学
In the nineteenth century, thousands of poor people struggled to survive in the slums of London. Diseases spread rapidly through the densely populated and unhealthy districts. At one time, over 600 people a week died of cholera, a fatal disease which was then thought to be spread by airborne germs.A young doctor, John Snow, was anxious to help the poor people. He obtained a map of the slums. On it he marked the building where each person had died. He soon noticed that most of the deaths occurred in a roughly circular area. The number of deaths was greatest around the center of the circle and then decreased as the distance from the center of the circle increased.This pattern was confirmed as Snow continued to record fresh deaths on his map.Snow concluded that at the center of the area there must be somebody or something that was causing or spreading cholera. When he went to the district, he saw a pump which brought water up from an open well. This was the sole source of water for people in the area. He examined a sample of the water and saw what it was discolored. He suspected that the water was contaminated, so he took the handle of the pump away, thus stopping people from drinking water from the well.Snow urged the city authorities to investigate the water in the well. At first they were reluctant to spend time and money on something which had not yet proved to be a danger. Snow continued to press for action, and eventually work men dug down to investigate the wall of the well. They found that it was cracked in several places and that raw sewage was seeping into it. The men filled in the well and dug another one where clean water could be obtained. The cholera epidemic slackened and then disappeared.The important point about Dr. Snow’s work was that he proved that cholera could be caught by drinking polluted water. This discovery was vital in attempts to fight the disease and helped to save thousands of lives in later years. It showed health workers what they should look for in campaigns to eliminate the disease and disproved the belief that the germs somehow drifted through the air.1. Snow apparently obtained a map of the slum district in order to ________.2. In Dr. Snow’s time, cholera was ________.3. When Snow first asked city officials to investigate the water in the well they ________.4. After the new well had been dug, the number of deaths from cholera ________.5. Snow took away the handle of the pump because ________.
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