B

    According to the World Health Organization (WHO), environmental pollution kills 1.7 million children under the age of five every year worldwide. The WHO warns that child deaths will increase greatly if pollution continues to worsen. Of all the environmental problems, air pollution is being called the most dangerous.

    Most of these deaths take place in developing countries. However, WHO environment and health chief Maria Neira tells that air pollution is a leveler between rich and poor. Everybody, she says, needs to breathe.

    “You can be a very rich child, your parents very rich, but living in a place, in a city, which is very polluted. Then there is very little you can do because we all need to breathe. Air pollution is everywhere.”

    Maria Neira says one of the most important ways to reduce air pollution is to produce cleaner fuels for cooking and heating.

    “Almost half of the world population is using dirty fuels for cooking, heating, and lighting at home. And, this is affecting very much mothers who are staying and cooking at home, but the children who are around mothers—they are exposed as well.”

    Cleaning up how the world cooks, heats and lights homes and other buildings is a big-picture goal.

    But what can every one of us do to limit our family to air pollution?

    The U.S. Environmental Protection Agency has the following suggestions:

    ● Avoid walking where there is a high volume of vehicle traffic.

    ● Equip homes with air filters and air conditioning units.

    ● Limit your time outside if you live in an area that issues warnings about air quality.

    ● Wear high-grade, rated face masks tightly to the face when air quality is poor.

    ● If you live or commute in a very polluted area, remove your clothes and wash immediately after entering your house.

    However, the WHO stresses that governments around the world need to take the lead on ensuring that children grow up in a clean environment.

    Many hundreds of years ago, the moon was a mystery to people on the earth. What was that glowing ball came out at night? Why did it keep getting smaller, then larger? Why didn't it fall from the sky? Through the ages, people have tried to come up with answers.

    To the native people of Bolivia, in South American, the moon was a great chief who once lived on the earth. The Abaluyian people of Kenya, in Africa, believe the moon and the sun were brothers who fought in the sky. In other parts of the world, people believed they saw different pictures in the moon. The Haida Indians of Canada saw a woman carrying a bucket. The Chinese saw a road.

    People in the past also used the moon to mark time as a kind of calendar. In fact, in some languages, the word for moon meant “month”. A Native American nation called the Sioux made a calendar of 13 moons, or months. Each moon had a name, such as Moon of Black Cherries, Moon of Green Corn, and Moon of Severe Cold.

    Though people of the past found the moon was helpful, mysterious and interesting, they didn't know much about it. They only knew what they could see with their own eyes.

    Then almost 400 years age, an Italian scientist named Galileo made a new telescope(望远镜) that was more powerful than any telescope made before. Galileo decided to take his new implement to look at the moon. He discovered that the moon was not the smooth, shiny ball. The brighter places were mostly hills and mountains. The flat areas were lower, which is why they appeared darker.

    As more people saw the moon through telescopes, they discovered more about it. Yet, people still had much to learn about the moon.

    Is human blood all the same? "Sure," you may say. "It's all red." Well, it's not as simple as you might know. Blood is made up of different pans, such as red blood cells, white blood cells, and platelets (血小板). Two chemical molecules (分子) on the red blood cells make people's blood different. Scientists mark one molecule "A" and the other molecule "B".

    According to which and how many molecules are on the red blood cell, scientists divide blood into four types: A, B, AB and O. Your blood type will stay the same through your whole life. Scientists have been wondering if there are some links between people's blood type and their personalities (个性), but they don't know for sure. Some say that people with the same blood type may have things in common.

    What's your blood type? Does your friend have the same blood type as you? Read the following.

    People with type A: They look peaceful from the outside. But they ask so much of themselves that they may be very agitated inside. They become happy or sad easily. Sometimes they are shy but always very careful. They can easily win people's trust.

    People with type B: They have strong minds. Once they begin a task and make up their minds to do it, they will not give up easily. They'll try their best to finish it and do it well. They always try to make themselves different from others. They want to do things in their own way.

    People with type AB: Maybe they are the strangest among all blood types. They can be both open and shy, noisy and quiet at the same time! They are responsible and always ready to help others.

    People with type O: They're open and good at making friends. They always begin tasks but don't always finish them in the end. They have lots of new ideas and love to be the centre of attention. They always strongly believe in themselves.

    What was discovered by accident? The answer is penicillin(青霉素). It kills germs. By killing germs, it saves lives. Suppose you are sick. You go to a doctor. She examines you. She says you have a "staph" infection(葡萄球菌感染). She gives you some medicine. You take it. The medicine knocks out the staph. Soon you are well. Before penicillin, this would not happen. Staph was almost sure death.

    Everyone wanted a medicine. Laboratories worked day and night. They grew the staph in small dishes. Then they tried to kill it. Nothing worked.

    The laboratory dishes had covers on them. They kept things from falling into dishes. Molds(霉菌)were a big worry. They are always in the air. You can't see them. They're too small .There are thousands of different molds. Molds can make an experiment (实验)fail. That's why dishes are covered.

    Dr. Alexander Fleming was working to kill the staph germ. He worked for years. One day he took a cover off a dish. He looked inside. There was a thick growth of staph germ. There was also some mold. Then he saw something strange. Where the mold was, there was no growth of staph. This is what Fleming probably thought. "By accident, I found a mold to kill the dreaded staph."

    This is how penicillin was found. But here's the real miracle(奇迹). There are thousands of kinds of molds. But only one kind can kill staph. The mold must have fallen into the dish a few days before. The cover was probably off only a few seconds(秒). In those few seconds the right mold fell into the right dish. Another mall might have thrown the dish away. But Fleming was very careful and smart. He understood what the mold did. How lucky the humans were!

    Lately, people have entered the forests where chimpanzees live. The chimpanzees have been getting sick because of people's diseases. In addition, people are hunting chimpanzees. Their number is becoming smaller and smaller.

    Chimpanzees live in the plains and forests of Africa. They eat many kinds of foods, from plant leaves and seeds to insects and even other small animals. Chimpanzees' favourite food is fruit.

    Chimpanzees are very clever and they can use tools well. They can catch bugs by using sticks, and break nuts by using rocks.

    The world's forests are much smaller than they were before. Roads were built in deep forests, so people start to enter the forests where chimpanzees live. That may lead to many problems. One problem for chimpanzees is that they can easily catch people's diseases and die.

Chimpanzees are much closer to people than monkeys.

    As it's easier for people to enter forests, they hunt more often. Young chimpanzees are caught to be pets or for scientific research. The young ones are taken away from the forests, and the adults are killed. Chimpanzees are likely to disappear in the future.

    How do animals communicate (交流) with each other? They have special "languages". In fact, they are using signals (信号). Different signals have different meanings.

    For example, when a bee (蜜蜂) finds food somewhere, it flies home quickly. It can't speak, but it can tell others by dancing. Other bees will know where and how far the food is.

    Some animals show their feelings by making sounds. For example, when a dog is angry, it barks (吠). At this time, you'd better stay away from it. Birds can make several sounds to show different meanings. Sometimes we humans show feelings by making sounds instead of by speaking. For example, when we feel painful (疼痛的), we cry "Oh!" or“Ouch!".

    We humans have languages and words. We can communicate face to face by speaking. We can write down what happened in order to remember clearly. We can also send (寄) messages to people far away. But animals can't.