One weekend in May 2015, over 48 centimeters of rain fell in Houston, Texas, USA. Soon the city was covered with water. The rising water rushed into the cars on the roads. There were 16 deaths that weekend.

      Changing Weather

      The weather is changing. Over the last few years, heavy rains have caused floods (洪灾) in Brazil, Pakistan, and Thailand. Droughts (干旱) have struck Russia and Australia. Heat waves have killed thousands in Europe. There are more different kinds of terrible wild weather all over the world. In 2011 alone, the bad weather caused the world to lose 150 billion dollars.　

      Warmer and Wetter

      As more wild weather events happen, a worried world is beginning to ask questions like: What is going on with the weather? And why? Many also want to know: Is this natural, or are we to blame (责怪)?

      The answer seems to be: a little of both. Wild weather is natural.   ▲   This global (全球的) warming makes heat waves more likely to happen. The higher temperatures also cause more water to enter the air. This causes much more rain. Some scientists also believe global warming makes some storms stronger.

      This means we're likely to see more wild weather. “But we don't have to just stand there and take it,” says Scientist Michael Oppenheimer. He and other scientists say we need to stop the Earth from getting warmer. We also need to be prepared, to do things that will help save lives.

    A taxi hit a truck. A policeman spoke to the taxi driver and to the truck driver. He also spoke to Tom. He was a witness (目击者). This is what they said.

    TRUCK DRIVER: I was driving from the airport to Newton. A car crossed the road, so I slowed down. I did not stop. A taxi hit the back of my truck. Nobody was seriously hurt but both cars were damaged（受损害）.

    TAXI DRIVER: I was driving behind a truck a few kilometers from Newton. The truck stopped suddenly. The driver did not give me a warning (警告). I was driving very slowly. I could not pass the truck because there were two cars coming near from Newton. My taxi hit the truck, and some glass cut my left hand.

TOM: I was watching the traffic about a kilometer from the airport. A truck was going to Newton. It was not going very quickly. There was a taxi about two hundred meters behind the truck. It was going fast. When the truck slowed down, the taxi hit it. The taxi driver was not looking at the truck. He was looking out of the window at something. My friend saw the accident, too.

    Tom's friend spoke to the policeman and agreed with Tom.

    People usually check whether their keys, purses and phones are with them before going out, but many people in China now have one more important thing to take--a mask(口罩). They hope it can protect them 1 terrible air.

    Many cities in China saw a lot of foggy days in April. In Beijing, there were eight days in April full of smog. It is dirty air 2 looks like a mixture of fog and smoke. The smoke is mainly from cars and factories in cities. Poor air is bad for people's health, 3 for children and old people. They fell ill easily and the 4 were full of people. They had problems with their noses and lungs.

    So it's necessary 5 people from doing so many bad things to the environment. For example, people should use cars less and   6 burn lots of coal and gas. Government needs to take measures to make factories stop pouring 7 waste air into the sky.

    Three students from No. 4 High School in Beijing 8 a report to advise how to protect the environment. They suggested  9people should plant more trees and act off fewer fireworks for celebration. We hope more people will join us in 10 a difference. In this way, the blue sky will certainly return for good.

   Do you want to live another 100 years or more? Some experts say that scientific advances will one day enable humans to last tens of years beyond what is now seen as the natural limit of the human life span.

    “I think we are knocking at the door of immortality(永生),” said Michael Zeya, a Montclair State University business professor and author of two books on the future. “I think by 2075 we will see it and that's a conservative estimate(保守的估计).”

    At the conference in San Francisco, Donald Luria, a professor at New Jersey Medical School in Newark said advances in using genes as well as nanotechnology(纳米技术) make it likely that humans will live in the future beyond what has been possible in the past. “There is a great push so that people can live from 120 to 180 years,” he said. “Some have suggested that there is no limit and that people could live to 200 or 300 or 500 years.”

    However, many scientists who study in ageing are doubtful about it and say the human body is just not designed to last past about 120 years. Even with healthier lifestyles and less disease, they say failure of the brain and organs will finally lead all humans to death.

    Scientists also differ on what kind of life the super aged might live. “It remains to be seen if you pass 120, you know; could you be healthy enough to have good quality of life?” said Leonard Pooh, director of the University of Georgia Gerontology Centre. “At present people who could get to that point are not in good health at all.”

    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.

    Some animals sleep during the wintertime because the weather can be very cold and it is difficult for them to find food. They can sleep for a long time. This kind of winter sleep is called “hibernation”.

    If an animal moves about a lot, it needs food. Hibernating animals do not need to eat much because they are not moving about. Their hearts(心脏) beat very slowly and they also breathe(呼吸) slowly. They find a place that is sheltered(遮蔽的) from bad weather and where they are out of danger. Their body fat(脂肪) keeps them alive and warm.

    Some animals, such as bears, may wake up from their hibernation on warm winter days and then quickly go back to sleep again when they see the snow is still thick on the ground. When the weather becomes warmer in spring, the animals start to wake up and look for food.