In many high schools, there are strict rules about using mobile phones. If your phone rings in class, for example, the teacher will be very angry.

    Every mobile phone has a ringtone (铃声). It tells you that someone is calling you. Now, there is a ringtone called "mosquitotone (蚊子铃声)". Using it, students can receive calls and text messages (短信) in class but the teacher will not realize what is happening. How?

    Mosquitotone has a special sound. Only children and teenagers can hear it. As we get older, we are unable to hear some sounds with high frequencies (频率). As a result, a child or teenager can hear the mosquitotone ringtone, but someone of 20 or older can't.

    But sometimes, people over 20 can hear the ringtone. One British student's phone uses mosquitotone. In class, the student's phone rang. The 22-year-old teacher looked at the student and became unhappy. "I heard that. You know the rule: no mobile phone in class."

    Not all the students are interested in mosquitotone. Jerry Jones, a high school student of 17, says, "Using mosquitotone too often is bad for our hearing. I may use it for pleasure, but not in class. It's unfair(不公平的) to the teachers!"

    What do parents think of mosquitotone? "I think it is perfect for places like movie theaters," says Connie Neeson, 44. "Think about it. You're watching a film and someone's mobile phone rings. Mosquitotone is good because many people don't hear it. However, it also has a bad influence（影响） on their study if students use it in class."

    Many wild animals, such as pandas, are in d{#blank#}1{#/blank#}. Often there is not e{#blank#}2{#/blank#} land or forests, so the animals do not have a safe place to live.

    There are only about 1,600 pandas in the wild today. Pandas do not have many babies, and baby pandas often d{#blank#}3{#/blank#}. The situation is getting more and more difficult. We need to p{#blank#}4{#/blank#} them.

    The government is s{#blank#}5{#/blank#} up nature parks and the pandas live in peace there.

    One of the hottest places on 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.

    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 saving water. It gets all the water it needs from the food it eats. The Sun makes the desert sand very hot. One snake, called the sidewinder, can solve this problem. When it travels, the sidewinder bends (弯曲) its body into a "W" shape. Then it uses the bottom 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 bum 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. One kind of fish, the desert pupfish, can live in these salty water because it can drink the salt water.

    The name of our galaxy(星系), the Milky Way, comes from its appearance. It's a milky white band of glowing light that spreads across the night sky. If you look up at the evening sky, there's a good chance you will not be able to see what your grandmother saw when she was a little girl. A new study says that nearly 80 percent of people in North America can't see the Milky Way because of light pollution.

    The most light-polluted country in the world is Singapore where researchers found that people living in the country never have the chance to experience true darkness. Other countries with large percentages of people living under such skies include Qatar, Kuwait and the United Arab Emirates.

    Too much light has a direct influence on human physiology and behavior. It can also destroy our sleep cycle. What's more, it also influences wildlife. For example, baby turtles may not swim into the ocean because of street lights near shorelines.

    In the U.S., some communities have been taking action on light pollution but in developing countries, people still want to make bigger, brighter light, like LED lights. They can save energy, but on the other hand, they will increase light pollution rapidly in fact.

    There are still people that can remember when they used to be able to see the Milky Way, when they would walk outside at night, but those are becoming fewer and fewer.

    Nighttime natural scenery needs protection just like daytime scenery. Don't let the light pollution steal the chance to experience the wonder of a natural night sky from us.

    Posted on 25 March by Selina

    I used to shower with soap every day, but my skin(皮肤)always felt dry and itchy(发痒的). Then two months ago, I heard of the no-soap movement. Since then, I've given up using soap in the shower. I still shower every day. I just don't use soap because it's filled with chemicals.

    So, what's so bad about using soap? Well, the chemicals in soaps can be harmful to our health. So, if we use soap, our skin will take in the chemicals, which will then end up in our bodies. According to the scientists, some of the chemicals used in a soap are quite dangerous. During my research, I also learnt that soap removes moisture(水分)from the body. This is actually why my skin was so dry and itchy.

    Getting used to washing my body without soap was a huge change. For the first week, I felt a bit dirty and I didn't smell great, either. However, during the second week, my skin felt clean without strange smell. Best of all, my skin problems disappeared, and now I have softer and healthier skin.

    On the whole, going soap-free has not only saved me time and money, but has also improved my skin. What's more, this experience has made me take a look at some of the other products I use in the shower, such as shampoo. More about that in my next blog!