John Snow was born and worked as a __36__ in Great Britain．Exactly, he was an anaesthetist，37 means that he put people to sleep during operation．He also began to experiment using the same drugs to help women when they had 38 ．That is why he became the doctor who 39 Queen victoria to give the birth of her babies．
At the time he lived，cholera was the most 40 disease．Neither its cause，nor its 41 was understood．So many thousands of people died 42 there was an outbreak．John Snow was 43 to help ordinary people 44 from cholera．He 45 the disease began in the stomach and the patients died quickly after severe vomiting(呕吐)and diarrhea (腹泄)．46 ，he believed cholera resulted from water．When another 47 hit London in 1854，John Snow set to work．
John Snow approached the problem in a systematic way．He marked on a map 48 all the dead people had lived and found many of the 49 were near a water pump．It seemed the water was the 50 ．So he collected information about the 51 habits of the dead people and used them eventually to prove his theory．With the information 52 ，John Snow was sure that 53 water was the cause．
Then people were required to 54 the water company to supply them with clean water．Thanks __55___ John Snow there was no more outbreaks of cholera．
A．scientist B．an official C. an officer D．doctor
A．who B．that C which D．it
A．pain B．ache C．difficulties D．babies
A．assisted with B．took care C．look after D．joined
A．surprising B．interesting C．interested D．frightening
A．cure B．method C．result D．threat
A．each time B．at one time C．in no time D．the first time
A．delighted B．devoted C．absorbed D．determined
A．suffered B．having suffered C．suffering D．being suffered
A．noticed B．was noticing C. has noticed D．had noticed
A．Therefore B. As a result of C．So D．According to
A．disease B．disaster C．outbreak D．case
A．how B．where C．what D．in which
A．women B．men C．death D．injuries
A．result B．cause C．origin D．case
A．drinking B．1iving C．working D．housing
A．having collected B．being collected C．collected D．collecting
A．being polluted B．polluted C. polluting D．having polluted
A．take on B．call on C．depend on D．carry on
A．to B．/ C．for D．on