QA- Read the comprehension and answer the questions:
In the city of London about 150 years ago, many people started to get extremely sick. The
sickness they had was called ‘cholera’. Lots of doctors tried to figure out how to prevent people
from getting cholera. They told their patients to open their windows and breathe in the fresh air
as much as possible or drink lots of water, but that did not help.
John Snow was a doctor and scientist who had a different idea. He thought that cholera might
have been spreading through the polluted water that people were drinking. At first, other doctors
and scientists disregarded Doctor Snow’s idea. They believed that cholera was spread through
the air and that water was not the problem.
Dr. Snow developed a plan to test his theory about polluted water causing cholera, so he went
to different neighborhoods in London and tested their water. It was just as he had thought! The
neighborhoods with the cleanest water had the fewest sick people. The places with the dirtiest
water had the greatest number of sick people.
Dr. Snow showed the results of his study to the mayor of London and the other doctors. They
examined the evidence and realized that Dr. Snow was right. All over London, people stopped
drinking water that might be polluted. Almost immediately, people stopped getting sick, and the
whole city was overjoyed.
