Soon computers and other machines will be able to remember you by looking at your eyes! The programme works because everyone's eyes are different. So in the future you won't have to remember a number when you want to use a machine or take money out of a bank. You'll just have to look at the machine and it will be able to tell who you are.
The eye-recognition programme is already being tested in shops and banks in the USA, Britain, Spain, Italy and Turkey. Soon, this technology will take the place of all other ways of finding out who people are.
However, scientists are working on other systems. Machines will soon be able to know you from the shape of your face or hand or even your smell! We already have machines that can tell who you are from your voice or the mark made by your finger.
Eye-recognition is better than other kinds because your eyes don't change as you get older, or get dirty like hands or fingers. And even twins have different eyes, so the programme can be up to 94％ correct, depending on how good the technology is. Some programmes may only be right  51％ of the time. In Britain, it was found that 91％ of people who had tried it said that they liked the idea of eye-recognition. In the future your computer will be looking you in the eye. So smile!

Where does the wind come from? What makes the wind move(移动) all the time? Scientists tell us that it is the sun. That makes air move, and makes it blow(吹). When the sun shines on the earth, it makes the earth hot. Then the earth makes the air hot. When the air becomes hotter, it also becomes lighter(更轻). The light air goes up. Cool air comes into take the place of（代替） the hot air. The hot light air goes up higher and higher until it becomes cool. Then it comes down again, and then the earth makes it hot again, and it has to go up. When the air move, it has wind.

    Have you ever seen a car without a driver? It sounds crazy, but these computer-driven driverless cars will soon be filling roads near you. Companies like Google and Tesla have been designing and testing these cars, and the technology is there.

    So how? The cars have sensors（感应器）all around which can find other cars and objects in the road. Road signs are read by cameras, and satellite navigation systems（卫星导航系统）are used so the car knows how to get where you want to go. All you have to do is type in the address! Finally, a central computer system takes in all the information that it receives from the sensors and cameras and works out when to speed up, stop and turn.

    Sound like your idea of heaven（天堂）? Sitting back, looking out of the windows and even watching a film or reading a book while ‘driving' would be possible with this new technology. You wouldn't have to worry about remembering directions to where you're going. In addition, computers would also drive more safely than people — they would obey the rules and have quicker action times when in dangerous situations.

However, there are many drawbacks of driverless cars. Computers would have difficulties making ethical（道德的）decisions: if a child ran into the road, would the computer choose to hit the child or turn suddenly and potentially kill the car's passengers? Moreover, I personally find driving fun –I'd miss never driving a car myself. There would also be many other decisions to be made –should children, or drunk people, be allowed in a driverless car by themselves? Or would there need to be a person with a driving license in the car at all times?

    I'm not certain I'd want a driverless car – but it's only a matter of time before they'll become more affordable and popular on our roads.

    March 20th is World Water Day every year. According to a report from the United Nations, more than half of the world's major rivers have serious water loss and are polluted.

    The Yellow River, the world's fifth longest river, watered some of the oldest farms on earth.

    {#blank#}1{#/blank#}Its source（源头）on Qinghai-Tibet Plateau is drying up. In most of the past 35 years, it didn't reach the sea.

    The Nile in Egypt, running 6, 650 km, is the longest river in the world.{#blank#}2{#/blank#}Now it is down to 2 billion m³ or so. Australia's Murray River reaches the sea only every other year. One fifth of America's Rio Grande has no water, either.

   {#blank#}3{#/blank#}

    Mostly it's damming（筑坝）and global warming that make rivers dry.{#blank#}4{#/blank#}Now about 45, 000 of them lie across the world's rivers. They hold back around 15% of the world's fresh water from running to the sea.

{#blank#}5{#/blank#}Warmer weather takes water away. The glacier（冰川）are becoming smaller. The source of the Yellow River is drying up because of it. Global warming has had certain effects on water sources. Droughts （干旱） happening around the world make people pay more attention to this fact.

    The kangaroo is the world's largest living marsupial (有袋动物). It was first found on the island of southwestern Australia. The animal was given its name by a famous English tourist in the 18th century.

    The kangaroo may be 7 feet(2.1m) tall when standing upright and the male can weigh as heavy as 200 pounds(90kg). The female (雌性) is smaller and lighter than the male. The kangaroo's head is small, but its ears are large, and its fore feet are really small. The animal has strong back legs and long tail.

    The kangaroo usually covers from 5 to 10 feet(1.5 to 3m) with each jump. The female is usually faster than the male. The mother kangaroo has a pouch (育儿袋) in its abdomen (腹部). The baby kangaroo grows up in the mother's pouch slowly.

    The kangaroo lives on grass and other plants. It is always moving from one place to another, lying down to sleep on the ground during the night. It likes to enjoy the warm sunshine. When it's in danger, it can use its back legs and strong tail to protect itself.

    Answer the following questions with No more than 6 words.

    When you watch TV and play video games you make global warming(全球变暖) worse! To make electricity, fossil fuels(矿物燃料) are burned in big factories. But burning fossil fuels also makes greenhouse gases. This means that every time you use electricity you help make global warming worse!

    Cars are also making global warming worse. They burn fossil fuels in their engines, and send lots of greenhouse gases into the air.

    So what can we do to stop global warming?

    Try to use less electricity. First, turn off lights, your television, and your computer when you stop using them，You could also try to watch less TV. But you may find it hard to do these! Second, plant trees. Not only is it a fun thing to do, but it is also a great way to lower the number of greenhouse gases in the air. Trees take carbon dioxide(二氧化碳) out of the air when they grow. Last, don't throw away your rubbish, but try to recycle it. Because if rubbish is not recycled, it rots(腐烂) and makes a greenhouse gas called methane(甲烷). So try to recycle cans, bottles, plastic bags and newspapers. It'll make you feel great! And it'll help the Earth.