Since the beginning of time, people have told stories and legends to explain natural, but mysterious events. The Northern Lights is one example. The Vikings thought the Northern Lights were caused by the shining weapon of immortal(长生的）warriors. The Alaskan Inuit people believed the lights were the souls of salmon, deer and other animals. The Menominee Indians thought the lights were the torches of huge men living in the North.

   The Northern Lights are actually caused by electron from solar winds. They are attracted to the poles by the magnetic (地磁的) fields found there. They mix with gases in the air, causing the gases to glow.Solar flares (耀斑) can also cause the Northern Lights to appear.

   Here are some fun facts about the Northern Lights.

   ★The name Aurora Borealis, another name for the Northern Lights, comes from two ancient names. Aurora is the Roman god of the dawn; Borealis is the Greek name for the

north wind.

   ★The Northern Lights are most visible to people living in the far north. People can sometimes see them as far south as Florida.

   ★The Northern Lights are typically green, purple, red or blue.

   ★Near the South Pole, people may see the Southern Lights or Aurora Australis. These lights are not easily visible

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.

What picture do you have of the future? Will life in the future be better, worse or the same as now? What do you hope about the future?

People predict that life will probably be very different in 2050. First of all, it seems that there won’t be TV channels (频道). At that time, people will pick up a program from a “menu” and a computer will send the program to the TV set at once. By 2050, music, films, programs, newspapers and books will come to us by computers.

In that time, water will become one of our most serious problems. In many places, farmers are in great need of water to grow fruit and vegetables.

In transportation, cars will run on new, clean fuels and they will go very fast. There won’t be any accidents because of robots. We will see robots everywhere. And space planes will take people around the world in two hours.

By 2050, we will be able to help blind and deaf people see again and hear again. At that time, people’s life will become better and better.

Most people around the world are right-handed. This also seems to be true in history. In 1799, scientists studied works of art made at different times from 1,500 B.C. to the 1950s. Most of the people shown in these works are right-handed, so the scientists guessed that right-handedness has always been common through history. Today, only about 10% to 15% of the world’s population is left-handed.

 Why are there more right-handed people than left-handed ones? Scientists now know that a person’s two hands each have their own jobs. For most people, the left hand is used to find things or hold things. The right hand is used to work with things. This is because of the different work of the two sides of the brain. The right side of the brain, which makes a person’s hands and eyes work together, controls the left hand. The left-side of the brain, which controls the right hand, is the centre for thinking and doing problems. These findings show that more artists should be left-handed, and studies have found that left-handedness is twice as common among artists as among people in other jobs.

 No one really knows what makes a person become left-handed instead of right-handed. Scientists have found that almost 40% of the people become left-handed because their main brain is damaged when they are born. However, this doesn’t happen to everyone, so scientists guess there must be another reason why people become left-handed. One idea is that people usually get right-handed from their parents. If a person does not receive the gene (基因) for right-handedness, he/she may become either right-handed or left-handed according to the chance and the people they work or live with.

 Though right-handedness is more common than left-handedness, people no longer think left-handed people are strange or unusual. A long time ago, left-handed children were made to use their right hands like other children, but today they don’t have to.

Soon computers and other machines will be able to remember you by looking at your eyes! The program works because everyone’s eyes are different. So in the future you won’t have to remember the number of your credit card 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（眼睛识别）program has already been tested in shops and

Eye-recognition is a course of recognizing iris（虹膜）, which includes the followingsteps. First, a kind of machine needs to collect different examples of one’s iris from hiseyes and store them. Second, when this person goes to the bank to take out money, this machine will have iris feature extraction（采集）. Then, this machine will compare the examples kept in it with iris feature extraction. Once the examples and the feature

extraction are the same, this person will be identified, and he will take out the money from the bank successfully.

However, scientists are also 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, and don’t get dirty like hands or fingers, and even twins have different eyes. So the eye-recognition program can be up to 94% correct, depending on how good the technology is. However, some other programs may only be 51% correct now. 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!

You can be proud of yourselves, even if you can only make one or two of these green changes. The goal here is to limit carbon dioxide and other greenhouse gases, which are closely connected to the big problem of global-warming (全球变暖).

   WAY 1: Bring your own cup to Starbucks. You’ll get a 10-cent discount, and it’s one less paper cup to end up in a dustbin. The store won’t create more waste when they throw away a cup.

   WAY 2: Turn off your computer. When in standby mode, your PC is still using energy. Turning off a monitor (显示器) for 40 hours a week may only save $ 5 a month, but it reduces CO₂by 750 pounds.

   WAY 3: Reuse plastic bags. Instead of throwing away 100 billion plastic bags a year, try and get a second, third, or tenth use out of them. Better yet, next time you shop, try a reusable bag. The amount of oil it would take to make just 14 plastic bags would run your car for one mile.

   WAY 4: Use recycled paper in the bathroom. Most of the toilet paper we use is made from trees found in forests. If every family replaced(替换)one roll of toilet paper with a recycled one, 424,000 trees would still be standing.

   WAY 5: Plant a tree. Adding green to your garden is beautiful and earth-pleasing. Just one tree will help make cleaner air and save the environment from 5, 000 pounds of hot carbon dioxide each year.

Pigs do it. Mice do it. Dogs also do it. Kangaroos? Not so much. Why do some animals shake? The short answer is because they are wet. But there’s actually more to it than that—a lot more.

In an article, Andrew Dickerson and others took a look at this strange problem. The scientists wrote down the shaking of 33 animals, of them are five kinds of dogs.

It shows that mammals（哺乳动物）can keep stronger by doing their cute little shakes. If they do not shake, animals would have to use up to 20 percent of their daily energy simply staying dry. And nearly all furry（有皮毛的）mammals shake to help themselves keep dry.

Those animals that are similar to kangaroos shake only part of their body. They usually live in dry places where keeping dry isn’t very hard. But not all animal shake in the same way. Also some shake less often than others.

Smaller animals seem to shake more quickly,30 shakes per second for a mouse, while bears, tigers and big dogs only about four.

In an interesting finding, Dickerson and his team have shown that these animals do the job as well as possible. In each example, the animals shake off about 70 percent of water in a few seconds. This should all be great to people. It takes us not seconds but minutes to dry our hair.

With the development of technology, WiFi is becoming more and more popular and important in people’s daily life.But have you ever experienced it? Just imagine what life will be like if there is no Internet.Maybe you won’t be able to talk with friends, play video games or search for information for your homework on the Internet.But in fact,only one third of the world’s population are able to get information on the Internet.The rest are too poor to buy WiFi access(使用    权) or they live in remote areas.As a result, they live without the Internet.

  Google and Facebook, two world-famous technology companies, have decided to do something about it.Google’s Project Loon will try to send balloons which are 15 meters wide into our Earth’s stratosphere(平流层) in 2015.The balloons are made of a special material that is three times thicker than the plastic bag we use every day.Each balloon will carry a minicomputer and a WiFi radio.The WiFi radio will send the Internet over the areas it is floating over.Then people can get up-to-date information on weather or news.

  Getting electricity has always been a problem for the 173 people living in Nuevo Saposoa, a small village inPeru,South America. However, things went from bad to worse in March 2015 after heavy rains damaged（毁坏） the only power cables in the area. The villagers were forced to use oil lamps（灯）, which are not only expensive but also dangerous because of the harmful gases they produce.

Luckily, researchers at the University of Technology (UT) in Lima,Peru heard about their problem and found a wonderful solution. They made a lamp that can be powered by plants and soil, both of which can be easily found in the Amazonian rainforest where the village lies. The lamp takes energy from a plant growing in a wooden box and uses it to light up an LED light bulb.

While that may sound amazing and even impossible, the science behind the idea is quite simple. As plants create their food (using the sun’s energy, water and chemicals from the soil), they also produce waste which they return to the soil. Tiny animals in the soil eat this waste and they produce electrons – the building blocks of electrical energy. The UT team put special sticks inside the soil to capture the energy and keep it in the lamp’s batteries for later use. The researchers say a single charge can power a 50-watt Led light for two hours - enough time for local villagers to get their evening work done.

The university gave ten Plant Lamps to the villagers of Nuevo Saposoa in October 2015. So far, they have been a huge success! Elmer Ramirez, the UT professor who invented the lamp, believes the Plant Lamp could help improve the lives of many people, especially small rainforest commu nities, 42% of whom have no electricity.

Waste can be seen everywhere in the school. Some students ask for more food than they can eat and others often forget to turn off the lights when they leave the classrooms. They say they can afford these things. But I don’t agree with them.

   Waste can bring a lot of problems. Although China is rich in some resources(资源)，we are short of others, for example, fresh water. It is reported that we will have no coal or oil to use in 100 years. So if we go on wasting our resources, what can we use in the future and where can we move? Think about it. I think we should say no to the students who waste things every day. Everybody should stop wasting as soon as possible.

   In our everyday life, we can do many things to prevent waste from happening, for example, turn off the water taps when we finish washing, turn off the lights when we leave the classroom, try not to order more food than we need, and so on. Little by little, everything will be changed. Waste can be stopped one day, if we do our best.