D．By saving the dying people suffering from cholera．

　 5．How was"King Cholera" defeated?

　 A．By not polluting the river again． B．By eating healthy diets．

　 C．By delivering the water from other rivers． D．By stopping drinking the polluted water．

　 6．What's the main idea of the passage?

　 A．John Snow was a well-known doctor in London．

　　B．The cause of cholera was polluted water．

　 C．The source of all drinking water supplies should be examined．

　　D．How John Snow collected，analyzed data and found the cause of cholera and solved it．

　 Fill in the blanks with the information from the text.

　 John Snow was an ________, who attended Queen Victoria as her personal _________, became inspired when he thought about helping ordinary people __________ to cholera. So many thousands of _________ people died every time cholera broke out. It was the __________for him to find its cause.

　 He became interested in two theories that possibly explained how cholera __________people. One was that cholera_________ in the air. The other was that people ________this disease into their bodies with their meals. From the stomach the disease quickly ________the body and soon the affected person __________.

　 After investigation, he found the water was to _________and that water coming from the river -was _________by the dirty water from London. He immediately told the _________people in Broad Street to remove the handle from the __________so that it could not be used.

　With the extra evidence John Snow was able to_ with certainty that _______water carried

　The .