Ⅱ.补全信息
选择正确选项填入空白处，补全所给句子提供的信息。
A．that bad air caused the disease
B．how it could be overcome
C．how cholera spread
D．that the water from the Broad Street pump had been infected
E．that the water from the pump carried cholera germs
F．that the water pump was to blame
1．Cholera used to be one of the most feared diseases in the world，until a British doctor，John Snow，showed ．
2．In general，doctors in those days had two contradictory theories to explain ．
3．One theory was ．
4．Snow suspected ．
5．As a result of this evidence，John Snow was able to announce ．
6．The truth was by waste.
