Better think twice before choosing a password for e-mail, online bank or shopping. Simple passwords are easy to be stolen.

A password is like a key to your home. If someone steals it, he'll get chances to steal something else. We use passwords everywhere in our life. We are so used to passwords that we don't pay any attention to them until we lose or forget one.
A study of 28,000 passwords recently stolen from a popular website showed that people often do the easy thing. It found that 16 percent took a first name as a password. Another 14 percent used the easiest keyboard combinations such as “12345678” or QWERTY. Five percent of the stolen passwords were names of television shows or stars popular with young people. Three percent of the passwords expressed feelings like “I don't care,” “Whatever,” “I love you,” or their opposite, “I hate you.”
Robert Graham, who did the study, advises people to choose a password that is longer than eight characters with one capital letter(大写字母) and one symbol.
Of course, safe passwords don't mean those hard to remember. Forgetting your password is sometimes a big headache for you. Maybe, the perfect password is easy for you and hard for others.

    More and more people like bicycling and it is no surprise. It is fun, healthy and good for the environment(环境). Maybe that's why there are 1. 4 billion bicycles and only 400 million cars on roads worldwide today. Bikes can take you almost anywhere, and there is no oil cost!

    Get on a bicycle and ride around your neighborhood. You may discover something new all around you. Stopping and getting off a bike is easier than stopping and getting out of your car. You can bike to work and benefit(受益) from the enjoyable exercise without polluting the environment. You don't even have to ride all the way.

    Folding(可折叠的) bikes work well for people who ride the train. Just fold the bike and take it with you. You can do the same on an airplane. A folding bike can be packed in a suitcase. You can also take a common bike with you when you fly. But be sure to look for information by getting on airline websites. Not all airlines are bicycle-friendly to travelers.

    Health Benefits of Bicycling:

    It helps to prevent heart diseases.

    Bicycling helps to control(控制) your weight.

    A 15-minute bike ride to and from work three times a week burns off five kilos of fat in a year.

    Bicycling can improve your mood(心情).

    Exercise like bicycling has been shown to make people feel better, more relaxed and self-confident.

    Bicycling is healthier than driving.

    One of the hottest places on the earth is Death Valley. It's a desert valley in North America. The animals in Death Valley don't use technology to keep cool. They have special abilities that help them live there.

    The kangaroo rat is one animal that lives in Death Valley. During the day in Death Valley, it gets hotter than 100°F. The kangaroo rat rests all day in a hole in the ground. It covers the hole with grass to keep out the heat. The kangaroo rat comes out at night when it is cooler. This little rat is also very good at conserving (节约) water. It gets all the water it needs from the food it eats. Some kangaroo rats never take a drink of water in their whole lives!

    The sun makes the desert sand very hot. Animals, like snakes, get too hot if they lie on the hot sand too long. One snake, called the sidewinder, can solve this problem. When it travels, the sidewinder bends (使弯曲) its body into a“W”shape. Then it uses the bottom (底部的) parts of the“W”like legs and walks sideways (向一侧). That way it touches only a little of the sand at a time, so the hot sand doesn't burn the snake. This strange way of moving is how the sidewinder got its name.

    A lot of water in the desert is too salty for most animals to drink. All water has some salt in it. As the desert heat dries up pools of water, the salt is left behind. The remaining water in these pools can be much saltier than the ocean. One kind of fish, the desert pupfish, can live in these salty pools because it can drink the salt water.

    Now, it seems that artificial intelligence (人工智能) is becoming more and more popular in life, and it has greatly influenced the ways we live, work and play. Can you imagine that you can play table tennis with a robot one day?

    Recently, a scientist has invented a special robot that can be a table, tennis coach. That means people can practice table tennis not only with humans but also with a robot.

    Named Forpheus, the smart table tennis robot is quite special. It can study the movements of human players and the speeds of the ball. In this way, it can exactly judge(判断) the players skill levels(KF). Then it uses the information to change the ways to play. If the players are just beginners, Forpheus will play in a slow and easy way, but if the players are better ones, the robot will play in a faster and more difficult way. What's more, while playing, it encourages players to try their best with words like "Good job!" ," Come on!" and so on. At the same time, it gives some good chance to improve their skills. So it is both a good partner and a clever coach. Science and technology is developing quickly these days and it's hard to imagine what will happen in the future. "In the next 20 years, it will be possible that one robot teaches another to play table tennis or even invents another one!" Takuoya, the inventor of the robot, said.

    Fresh green grass, Hundreds of colorful wild flowers. Water running into little pools. Birds making their homes in boxes. The 9, 500-square-metre Augustenborg Botanical Garden may look just like any other well-organized park but there's a difference. It lies on the roofs (屋顶) of industrial and office buildings in the city of Malmo in Sweden.

    Green roofs are not a new invention. And now they are getting popular again. The common roofs of a modern city have endless black surfaces with no life or water. Perhaps that's why a garden on a roof becomes such a perfect choice for more and more people.

    Green roofs are not just pretty. They also help to moderate the city temperature. The high temperatures on common roofs in the summer can make top floor flats uncomfortably hot. What is more, they play a part in making the cities hotter than the countryside around them, causing the "urban heat-island effect". On a green roof, however, with its plants and water, temperatures change only a little, as they do in a park. This can greatly cut the costs of heating and cooling in the building below.

    Also, a green roof takes in rain water, and protects the city drainage (排水) system.   ▲    And small animals and birds can make their homes on it. Thanks to this, the city may become part of nature, rather than something completely separate from it.

    While the cost of building such a roof can still be higher, it can be cheaper in the long term as a result of energy savings. And wouldn't it be wonderful to be able to walk out into a garden high above the city's noise and traffic, whether you're at school or in an office or just at home in a ten-floor block?

    Thousands of years ago. in the south of ancient China, there lived Shennong, a man who had an ox(牛) head and human body. Seeing that local people were suffering from disease, he built ladders and houses on a high mountain to store hundreds of medical plants. To remember him, people named the place Shennongjia.

    The legend(传说) makes Shennongjia in Hubei an inviting place for tourists. Travelling there is a unique experience, as you can see sceneries of the four seasons from different altitudes. “When the bottom of the mountain is summer, the top is spring and while the foothill is autumn, the top is covered with ice," local people say of the special climate of Shennongjia.

    Shennongjia is also home to 5, 000 species of animals and plants. Many animals in danger live there, such as the golden monkey, the clouded leopard and the Asian black bear.

    One interesting and mysterious thing about Shennongjia is its legend of wild men. Some people once claimed that they saw big footprints or big-foot creatures. Yet so far, scientists haven't proved it is true and some say they are just bears.

    The beautiful place has recently received a new title. On July 17, 2016, Shennongjia Forestry District was added to United Nations World Heritage list as a natural site. China now has 52 world heritage sites(遗址)，second only to Italy in the world.