About cholera •It was a 1.________ disease of its day.

•People didn't know its cause or its 2.____.

•Many thousands of people died every time there was an outbreak. Two theories •Cholera spread in a cloud of dangerous gas.

•Cholera was 3.________ into people's bodies with their meals. The course of finding evidence •As the disease spread quickly through poor 4.________ of London，John Snow began to gather information.

•He found the outbreak was very 5.______ in two particular streets. •After further investigations he discovered it seemed that the water was to 6.________.

•When people didn't use the 7.________ water，the disease slowed down，which showed that cholera was really spread by germs. 8.________ to prevent cholera from happening •John Snow suggested that the 9.______ of all the water supplies be examined.

•The water companies were 10.______ not to expose people to polluted water any more. IV. 根据提示复述课文

John Snow ... ... ...in the 19th century. He ... ... ...in order to defeat it. In 1854 ... ... .... He marked on a map where ... ... ... and he found that ... ... ...died. So he decided ... ... .... He suggested that the source of all water supplies ... ... .... Finally, ... ... ....