Do you know what the hump(驼峰) of a camel is used for? If you answered to store water, guess again. In fact, a camel's hump is a place for storing fat.

    Most animals, including humans, store fat throughout their bodies, under their skin. But camels store their fat in one place, their hump. A hump can weigh as much as 80 pounds. Why do camels keep their fat this way? The answer is most likely because of their environment. Camels can go up to two weeks without eating because they have this fat to live off.

    Also camels are great at handling(处理，应付) changes in body temperature. Their humps can help the camels keep cooler. Their coats also help them adapt(适应) to the heat. While the coat is thick, it reflects(反射)the sunlight and protects the camel from the heat that rises off the desert sand.

    There are two kinds of camels, those with one hump and those with two humps. Camels with one hump are called Dromedary or Arabian camels. They live in the dry deserts in West Asia. Camels with two humps are called Bactrian camels. They live in Central and East Asia.

    Besides their humps, camels have a lot of interesting facts. They can live between 40~50 years. They can carry about 400 pounds and run up to 40 miles per hour. It's true that camels can go long time without drinking water, and they can drink about 26 gallons of water at a time. Camels can also close their nostrils(鼻孔). So whether a camel has one hump or two, it is one amazing animal that is very well adapted to its environment.

    If you travel by air across the center of Africa or South America, you fly over forests for thousands of kilometres．These great forests are the seas of trees．They are full of thousands and thousands of different kinds of plants and animals．However, the world's forests are getting smaller all the time．We are cutting down the trees because we need wood, and we need more farmland as well．Some people say that there will not be any forests like these left in 20 to 30 years．What will happen if they disappear? If we cut down our forests, a lot of plants and animals will disappear from the world, in a lot of places the new farmland will soon look like the old deserts, for example, crops will not grow there．What's worse, it will not rain very often, and the weather will get very hot．Perhaps the climate of the world will change, which will be dangerous for everyone in the world．That is why we must take care of our forests．

    Have you ever heard robot fish? Scientists will put some robot fish into the sea near Spain. These robot fish will help people to detect (探测) the pollution in the water. If the robot fish are able to finish their work successfully, the scientists hope to put them into rivers, lakes and seas around the world.

    The fish are about 1.5 meters long. There will be a detector in their bodies. They can find the sources (来源) of pollution in the water, and then the robot fish will eat part of it. Unlike other robots, they don't need to be controlled by people far away. The robot fish all have an eight-hour battery (电池). They can "swim" in the sea freely and send back information to people on the beach. After their batteries die, they will return by themselves.

    There are five robot fish altogether now. Each costs about 29,000 dollars. They are part of a three-year project between engineering company BMT Group and Essex University in southeastern England.

    "We invented the robot fish creatively. We hope them can find the changes in the sea water and report back the information," said Professor Hu of Essex University. His team is developing the fish.

    These days haze(雾霾) is around us here and there. In fact, everyone has the power to change their living habits to help reduce it. Many local governments call on their people to take action to make the air cleaner.

    Transport is one of the biggest contributors(促成物) to haze. When, where, bow, why and what you drive all affect air quality. When one drives to work for one year, he uses as much energy as a bus rider uses in 10 years. So walk or ride your bicycle to work or school whenever possible. If it is necessary, you can use public transport instead of your car. Each person using public transport for a year instead of a car can save nearly a tonne of pollutants, including CO₂, from going into the atmosphere.

    Carpooling is another way to reduce carbon emissions (排放). Carpooling is the sharing of car journeys so that more than one person travels in a car. It immediately reduces your car's emissions by half.

    What you do inside your living space can have a big effect on the air quality outside it. You can do a lot of things inside and around your home that will help you pollute less and save some money.

    A large amount of our energy supply comes from burning coal, another contributor to haze. By cutting down your electricity use, you are cutting down on haze. So you may try to reduce your use of electricity by turning off lights, using your air conditioner wisely during the summer months, or updating some of your electrical appliances to low-energy models. For example, you can use energy-saving lamps that require less energy and last 10 times longer than common bulbs.

    Once people thought that dinosaurs were brown or gray in colour, but the answer is to be found out. After examining the remains of a dinosaur, scientists say the colour of the feathers is bright. American and Chinese scientists rebuilt the feathers of a flightless(不能飞的)dinosaur

that lived about 150 million years ago, and researchers studied melanosomes(黑素体)in the feathers. The researchers compared them to the melanosomes that control the colour of feathers on modern birds. They were then able to make out the colours of dinosaurs' feathers. Richard Prum, a biologist(生物学家)at Yale University, said the dinosaur would be a beautiful creature if it were still alive. The discovery is useful to scientists in another way. It helps them better understand not only how dinosaurs looked but also how they lived in their daily life. Some researchers plan to use this way to study the colours of other feathered dinosaurs.

    Let me tell you something about sharks. Sharks are among the oldest animals in the world. There are over three hundred and fifty different kinds of sharks in the world. Most sharks are about two meters long and live in the oceans.

    A shark can smell something in the water, for example, the blood of animals. That helps them find their food. Sharks mainly eat fish, other sharks and plants in the ocean.

    Most sharks bite (咬)people by mistake. They think a person is a large sea animal. When the sun goes down or comes up, sharks are looking for food. So at these times people shouldn't go swimming in the ocean. Today people kill sharks for food and their skin. The number of sharks in the world is dropping fast.