人教版高中英语必修五电子课本

2021年1月25日发(作者：夏天的英文)
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必修
5 Unit 1

JOHH SHOW DEFEATS “KING CHOLERA”

John Snow was a famous doctor in London - so expert, indeed, that he attend
ed Queen Victoria as her personal physician. But he became inspired when he tho
ught about helping ordinary people exposed to cholera. This was the deadly dise
ase of its day. Neither its cause nor its cure was understood. So many thousand
s of terrified people died every time there was an outbreak. John Snow wanted t
o face the challenge and solve this problem. He knew that cholera would never b
e controlled until its cause was found.

He became interested in two theories that possibly explained how cholera ki
lled people. The first suggested that cholera multiplied in the air. A cloud of
dangerous gas floated around until it found its victims. The second suggested
that people absorbed this disease into their bodies with their meals. From the
stomach the disease quickly attacked the body and soon the affected person die
d.



John Snow suspected that the second theory was correct but he needed eviden
ce. So when another outbreak hit London in 1854, he was ready to begin his enqu
iry. As the disease spread quickly through poor neighbourhoods, he began to gat
her information. In two particular streets, the cholera outbreak was so severe
that more than 500 people died in ten days. He was determined to find out why.



First he marked on a map the exact places where all the dead people had liv
ed. This gave him a valuable clue about the cause of the disease. Many of the d
eaths were near the water pump in Broad Street (especially numbers 16, 37, 38 a
nd 40). He also noticed that some houses (such as 20 and 21 Broad Street and 8
and 9 Cambridge Street) had had no deaths. He had not foreseen this, so he made
further investigations. He discovered that these people worked in the pub at 7
Cambridge Street. They had been given free beer and so had not drunk the water
from the pump. It seemed that the water was to blame.



Next, John Snow looked into the source of the water for these two streets.
He found that it came from the river polluted by the dirty water from London. H
e immediately told the astonished people in Broad Street to remove the handle f
rom the pump so that it could not be used. Soon afterwards the disease slowed d
own. He had shown that cholera was spread by germs and not in a cloud of gas.



In another part of London, he found supporting evidence from two other deat
hs that were linked to the Broad Street outbreak. A woman, who had moved away f
rom Broad Street, liked the water from the pump so much that she had it deliver
ed to her house every day. Both she and her daughter died of cholera after drin
king the water. With this extra evidence John Snow was able to announce with ce
rtainty that polluted water carried the virus.



To prevent this from happening again, John Snow suggested that the source o
f all the water supplies be examined. The water companies were instructed not t
o expose people to polluted water any more. Finally
d.



COPERNICUS’ REVOLUTIONRRY THE
ORY



Nicolaus Copernicus was frightened and his mind was confused. Although he h
ad tried to ignore them, all his mathematical calculations led to the same conc
lusion: that the earth was not the centre of the solar system. Only if you put
the sun there did the movements of the other planets in the sky make sense. Yet
he could not tell anyone about his theory as the powerful Christian Church wou
ld have punished him for even suggesting such an idea. They believed God had ma
de the world and for that reason the earth was special and must be the centre o
f the solar system.



The problem arose because astronomers had noticed that some planets in the
sky seemed to stop, move backward and then go forward in a loop. Others appeare
d brighter at times and less bright at others. This was very strange if the ear
th was the centre of the solar system and all planets went round it.



Copernicus had thought long and hard about these problems and tried to find
an answer. He had collected observations of the stars and used all his mathema
tical knowledge to explain them. But only his new theory could do that. So betw
een 1510 and 1514 he worked on it, gradually improving his theory until he felt
it was complete.



In 1514 he showed it privately to his friends. The changes he made to the o
ld theory were revolutionary. He placed a fixed sun at the centre of the solar
system with the planets going round it and only the moon still going round the
earth. He also suggested that the earth was spinning as it went round the sun a
nd this explained changes in the movement of the planets and in the brightness
of the stars. His friends were enthusiastic and encouraged him to publish his i
deas, but Copernicus was cautious. He did not want to be attacked by the Christ
ian Church, so he only published it as he lay dying in 1543.



Certainly he was right to be careful. The Christian Church rejected his the
ory, saying it was against God's idea and people who supported it would be atta
cked. Yet Copernicus' theory is now the basis on which all our ideas of the uni
verse are built. His theory replaced the Christian idea of gravity, which said
things fell to earth because God created the earth as the centre of the univers
e. Copernicus showed this was obviously wrong. Now people can see that there is
a direct link between his theory and the work of Isaac Newton, Albert Einstein
and Stephen Hawking.

必修
5 Unit 2



PUZZLES IN GEOGRAPHY