课例1必修5 Unit 1 Great Scientists
John Snow Defeats “King Cholera”
John Snow was a famous doctor in London — so expert, indeed, that he attended Queen Victoria as her personal physician. But he became inspired when he thought about helping ordinary people exposed to cholera. This was the deadly disease of its day. Neither its cause nor its cure was understood. So many thousands of terrified people died every time there was an outbreak. John Snow wanted to face the challenge and solve this problem. He knew that cholera would never be controlled until its cause was found.
He became interested in two theories that possibly explained how cholera killed 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 6 people absorbed this disease into their bodies with their meals. From the stomach the disease quickly attacked the body and soon the affected person died.
John Snow suspected that the second theory was correct but he needed evidence. So when another outbreak hit London in 1854, he was ready to begin his enquiry. As the disease spread quickly through poor neighbourhoods, he began to gather 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 lived. This gave him a valuable clue about the cause of the disease. Many of the deaths were near the water pump in Broad Street (especially numbers 16, 37, 38 and 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. He immediately told the astonished people in Broad Street to remove the handle from the pump so that it could not be used. Soon afterwards the disease slowed down. 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 deaths that were linked to the Broad Street outbreak. A woman, who had moved away from Broad Street, liked the water from the pump so much that she had it delivered to her house every day. Both she and her daughter died of cholera after drinking the water. With this extra evidence John Snow was able to announce with certainty that polluted water carried the virus.
To prevent this from happening again, John Snow suggested that the source of all the water supplies be examined. The water companies were instructed not to expose people to polluted water any more. Finally “King Cholera” was defeated.
课例2必修2 Unit 2 The Olympic Games
An Interview
Pausanias, who was a Greek writer about 2,000 years ago, has come on a magical journey on March 18th 2007 to find out about the present-day Olympic Games. He is now interviewing Li Yan, a volunteer for the 2008 Olympic Games.
P: My name is Pausanias. I lived in what you call “Ancient Greece” and I used to write about the Olympic Games a long time ago. I've come to your time to find out about the present-day Olympic Games because I know that in 2004 they were held in my homeland. May I ask you some questions about the modern Olympics?
L: Good heavens! Have you really come from so long ago? But of course you can ask any questions you like. What would you like to know?
P: How often do you hold your Games?
L: Every four years. There are two main sets of Games — the Winter and Summer Olympics, and both are held every four years on a regular basis. The Winter Olympics are usually held two years before the Summer Games. Only athletes who have reached the agreed standard for their event will be admitted as competitors. They may come from anywhere in the world.
P: Winter Games? How can the runners enjoy competing in winter? And what about the horses?
L: Oh no! There are no running races or horse riding events. Instead there are competitions like skiing and ice skating which need snow and ice. That's why they're called the Winter Olympics. It's in the Summer Olympics that you have the running races, together with swimming, sailing and all the team sports.
P: I see. Earlier you said that athletes are invited from all over the world. Do you mean the Greek world? Our Greek cities used to compete against each other just for the honour of winning. No other countries could join in, nor could slaves or women!
L: Nowadays any country can take part if their athletes are good enough. There are over 250 sports and each one has its own standard. Women are not only allowed, but play a very important role in gymnastics, athletics, team sports and ...
P: Please wait a minute! All those events, all those countries and even women taking part! Where are all the athletes housed?
L: For each Olympics, a special village is built for them to live in, a main reception building, several stadiums for competitions, and a gymnasium as well.
P: That sounds very expensive. Does anyone want to host the Olympic Games?
L: As a matter of fact, every country wants the opportunity. It's a great responsibility but also a great honour to be chosen. There's as much competition among countries to host the Olympics as to win Olympic medals. The 2008 Olympics will be held in Beijing, China. Did you know that?
P: Oh yes! You must be very proud.
L: Certainly. And after that the 2012 Olympics will be held in London. They have already started planning for it. A new village for the athletes and all the stadiums will be built to the east of London. New medals will be designed of course and ...
P: Did you say medals? So even the olive wreath has been replaced! Oh dear! Do you compete for prize money too?
L: No, we don't. It's still all about being able to run faster, jump higher and throw further. That's the motto of the Olympics, you know ... “Swifter, Higher and Stronger.”
P: Well, that's good news. How interesting! Thank you so much for your time.
课例3 必修3 Unit 4 Astronomy: the Science of the Stars
How Life Began on The Earth
No one knows exactly how the earth began, as it happened so long ago. However, according to a widely accepted theory, the universe began with a “Big Bang” that threw matter in all directions. After that, atoms began to form and combine to create stars and other bodies.
For several billion years after the “Big Bang”, the earth was still just a cloud of dust. What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. The earth became so violent that it was not clear whether the shape would last or not. It exploded loudly with fire and rock. They were in time to produce carbon, nitrogen, water vapour and other gases, which were to make the earth's atmosphere. What is even more important is that as the earth cooled down, water began to appear on its surface.
Water had also appeared on other planets like Mars but, unlike the earth, it had disappeared later. It was not immediately obvious that water was to be fundamental to the development of life. What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas. This produced a chain reaction, which made it possible for life to develop.
Many millions of years later, the first extremely small plants began to appear on the surface of the water. They multiplied and filled the oceans and seas with oxygen, which encouraged the later development of early shellfish and all sorts of fish. Next, green plants began to grow on land. They were followed in time by land animals. Some were insects. Others, called amphibians, were able to live on land as well as in the water. Later when the plants grew into forests, reptiles appeared for the first time. They produced young generally by laying eggs. After that, some huge animals, called dinosaurs, developed. They laid eggs too and existed on the earth for more than 140 million years. However, 65 million years ago the age of the dinosaurs ended. Why they suddenly disappeared still remains a mystery. This disappearance made possible the rise of mammals on the earth. These animals were different from all life forms in the past, because they gave birth to young baby animals and produced milk to feed them.
Finally about 2.6 million years ago some small clever animals, now with hands and feet, appeared and spread all over the earth. Thus they have, in their turn, become the most important animals on the planet. But they are not looking after the earth very well. They are putting too much carbon dioxide into the atmosphere, which prevents heat from escaping from the earth into space. As a result of this, many scientists believe the earth may become too hot to live on. So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.
课例4必修2 Unit 4 Wildlife Protection
How Daisy Learned to Help Wildlife
Daisy had always longed to help endangered species of wildlife. One day she woke up and found a flying carpet by her bed. “Where do you want to go?” it asked. Daisy responded immediately. “I'd like to see some endangered wildlife,” she said. “Please take me to a distant land where I can find the animal that gave fur to make this sweater.” At once the carpet flew away and took her to Tibet. There daisy saw an antelope looking sad. It said, “We're being killed for the wool beneath our stomachs. Our fur is being used to make sweaters for people like you. As a result, we are now an endangered species.” At that Daisy cried, “I'm sorry I didn't know that. I wonder what is being done to help you. Flying carpet, please show me a place where there's some wildlife protection.”
The flying carpet traveled so fast that next minute they were in Zimbabwe. Daisy turned around and found that she was being watched by an elephant. “Have you come to take my photo?” it asked. In relief Daisy burst into laughter. “Don't laugh,” said the elephant, “We used to be an endangered species. Farmers hunted us without mercy. They said we destroyed their farms, and money from tourists only went to the large tour companies. So the government decided to help. They allowed tourists to hunt only a certain number of animals if they paid the farmers. Now the farmers are happy and our numbers are increasing. So good things are being done here to save local wildlife.”
Daisy smiled, “That's good news. It shows the importance of wildlife protection, but I'd like to help as the WWF suggests.” The carpet rose again and almost at once they were in a thick rainforest. A monkey watched them as it rubbed itself. “What are you doing?” asked Daisy. “I'm protecting myself from mosquitoes,” it replied. “When I find a millipede insect, I rub it over my body. It contains a powerful drug which affects mosquitoes. You should pay more attention to the rainforest where I live and appreciate how the animals live together. No rainforest, no animals, no drugs.”
Daisy was amazed. “Flying carpet, please take me home so I can tell WWF and we can begin producing this new drug. Monkey, please come and help.” The monkey agreed. The carpet flew home. As they landed, things began to disappear. Two minutes later everything had gone — the monkey, too. So Daisy was not able to make her new drug. But what an experience! She had learned so much! And there was always WWF ...