As we all know, cholera is a 【小题1】 disease which once 【小题2】 over people all over the world every time it 【小题3】. At first, people 【小题4】 it was due to bad air. 【小题5】 John Snow, the truth was found out that the polluted water was 【小题6】. Since the cause was known, cholera was defeated 【小题7】.

In the early 19th century, when a 【小题1】 cholera hit Europe, John Snow became frustrated because no one knew how to prevent or treat cholera. But he never lost his desire to destroy cholera once and for all. Snow subscribed to the theory that cholera was caused by an 【小题2】 from germs in food or water but he needed 【小题3】. Snow began by marking on a map the exact places where all those who died had lived. As a result, John Snow was able to announce that the pump water was to 【小题4】. Accordingly, he had the handle of the pump removed so that it could not be used. Through this 【小题5】, the disease was stopped in its tracks.