growing mountain of electronic waste like computers and personal digital assistants. The electronic waste stream is

increasing three times faster than traditional garbage as a whole.

        Electronic devices contain valuable metals such as gold and silver. A Swiss study reported that while the 

weight of electronic goods represented by precious metals was relatively small in comparison to total waste, the 

concentration (含量) of gold and other precious metals was higher in            So-called e-waste than in naturally 

occurring minerals.

         Electronic wastes also contain many poisonous metals. Even when the machines are recycled and the harmful 

metals removed, the recycling process often is carried out in poor countries, in practically uncontrolled ways which 

allow many poisonous substances to escape into the environment.

         Creating products out of raw materials creates much more waste material, up to 100 times more, than the 

material contained in the finished products. Consider again the cell-phone, and imagine the mines that produced 

those metals, the factories needed to make the box and packaging(包装) it came in. Many wastes produced in the

producing process are harmful as well.

        The U.S. Environmental Protection Agency notes that most waste is dangerous in that “the production, 

distribution, and use of products — as well as management of the resulting waste — all result in greenhouse gas 

release.” Individuals can reduce their contribution by creating less waste at the start — for instance, buying 

reusable products and recycling.

        In many countries the concept of extended producer responsibility is being considered or has been put in place 

as an incentive (动机) for reducing waste. If producers are required to take back packaging they use to sell their 

products, would they reduce the packaging in the first place?

Governments' incentive to require producers to take responsibility for the packaging they produce is usually

based on money. Why, they ask, should cities or towns be responsible for paying to deal with the bubble wrap (气

泡垫) that encased your television?

From the governments' point of view, a primary goal of laws requiring extended producer responsibility is to

transfer both the costs and the physical responsibility of waste management from the government and tax-payers 

back to the producers.

Ways to protect cell phones from damage

    While people use cell phones frequently, very few take the necessary measures to prevent damage. {#blank#}1{#/blank#} Here are some simple ways for you to protect your cell phone from damage.

Keep cell phones out of the rain

    If you must talk on the phone while it's raining, try to move indoors.  {#blank#}2{#/blank#} Otherwise, you may have trouble with the numbers or the cell phone speaker. Imagine dialing (拨打) one number and getting different results.

{#blank#}3{#/blank#}

    Many people like to put their cell phones in the pants or jeans pocket. However, storing a cell phone there will put it at risk of damage. You may forget that it is still in your pocket and just sit on the cell phone. As a result, your cell phone screen will get damaged.

Do not handle cell phones while eating

    {#blank#}4{#/blank#} This is especially true for those times when you are eating messy things and get the ingredients on your hands. One accident can cause lots of damage for your cell phone.

Get a protective cell phone case

    There are many kinds of cases available on the market. {#blank#}5{#/blank#} It will provide a protective cushion (垫子) that may save you from paying money to fix or buy a new phone.

    Both instructors and learners can get benefits from the following learning strategies as long as they are properly made use of in language learning.

{#blank#}1{#/blank#}

    The information presented in this section focuses on specific conversation, discussion, or presentation skills. The activities are generally self-explanatory, with students expressing opinions, making decisions, solving problems, planning presentations, and so on. Engaged in these activities, students have the possibility of communicating with each other in class. This section also includes lists of expressions used to illustrate different language functions, such as agreeing, disagreeing, and asking for clarity in order to help students expand their knowledge of English.

{#blank#}2{#/blank#}

    In a speaking or listening course, students' anxieties can affect their learning. For this reason, it is important to establish a friendly, relaxed classroom environment. It may help students 10 think of the classroom as a laboratory where they can experiment and take risks with the language. In such circumstances, students should realize that errors are a natural and expected part of learning a language. In addition, one of the goals of this pan is to encourage students to examine their awn opinions and values while at the same time showing respect for the opinions and values of others.

{#blank#}3{#/blank#}

    Many of the activities in this section involve the students' cooperating work in class. Generally, such an activity taken up by four members seem to work the best. Groups of three or five members may also be effective, depending on the activity. The first unit includes guidelines for organizing group work, with students taking on the following roles: leader, reader, summarizer, reporter, and observer (if necessary). Organizing all activities in this way makes the course truly learner-centered since students must take fall responsibility for carrying out each activity. As for seating, group members should arrange their seats or chairs in a small circle to encourage interaction.

{#blank#}4{#/blank#}

    Being a teacher, in the course of group activities, you should circulate from group to group, which helps ensure that students are on task and are using English. While you should not participate in pair or group activities, you need to stay involved in what the students are doing. One important reason to circulate during activities is to keep track of the kinds of problems students have, such as grammatical accuracy, fluency, word choice, pronunciation and intonation discussion strategies, etc. However, it is generally not effective to correct students' errors when they arc involved in an activity. The most practical way to deal with communication problems is to make notes of what you observe as you arc circulating. You can then use this information to provide feedback after the activity or to develop future lessons.

{#blank#}5{#/blank#}

    At the beginning of the course, when they need to build up their confidence, students benefit most from encouragement and positive comment. If possible, you'd rather not grade the students fust few efforts at speaking in a group or to the class. Many students suffer such anxiety in speaking situations that any criticism at this stage can have the opposite effects. Commenting on students' work does not necessarily mean grading them on the scene. Even if the programs requires formal grades, you should try to put off assigning grades until later in the term.

    Have you ever awakened and felt like you couldn't move? If so, it probably scared you. You may have thought something terrible had happened to you. Actually, many people have this experience on a regular basis. It is called sleep paralysis. Although it sounds scary, it is normal.

    Sleep paralysis happens when a person is falling asleep or waking up. As the person falls asleep, his or her body slowly relaxes. Usually the person's mind relaxes at the same time, but occasionally the mind stays awake longer than the body. As a result, the person can be conscious, or aware, but have trouble moving or speaking. Sleep paralysis can also occur as you wake up. Fortunately, the condition rarely lasts for more than a few seconds. Movement and speech soon return to normal.

    Some people report unusual experiences during sleep paralysis. They may hear, see, or feel things that don't exist. At one time, people thought that ghosts or monsters had entered the room and were holding them down, keeping them from moving. Science has helped us understand that such visions are actually a part of sleep paralysis. Now we know that getting too little sleep, taking certain medications, and changing your sleep schedule can cause sleep paralysis. This condition can be scary if you, but it's just a trick that your mind is playing on your body.

    They still bite, but new research shows lab-grown mosquitoes are fighting dengue fever — a dangerous disease that they normally would spread. Dengue infections appear to be dropping fast in communities in Indonesia, Vietnam, Brazil and Australia that are filled with the specially grown mosquitoes.

    Researchers first injected (注射)mosquito eggs with Wolbachia bacteria that's common in insects and harmless to people in a lab. Infected females then pass the bacteria on through their eggs. Releasing enough Wolbachia carriers, both the females that bite and the males that don't, allows mating(交配)to spread the bacteria through a local mosquito population.

    Rather than using chemicals to wipe out pests, "this is really about transforming the mosquito," said Cameron Simmons of the nonprofit World Mosquito Program, which is conducting the research.

    The first success came from Australia. Mosquitoes carrying Wolbachia were released in parts of North Queensland starting in 2011, and gradually spread through the local mosquito population. Dengue is spread when a mosquito bites someone who is infected, and then bites another person, but somehow Wolbachia blocks that — and local spread has nearly disappeared in those North Queensland Communities, Simmons said.

    The studies are continuing in other countries. But the findings, presented at a meeting of the American Society for Tropical Medicine and Hygiene, suggest it's possible to turn at least some mosquitoes from a public health threat into annoying biters.

    The work marks "exciting progress," said Michigan State University professor Zhiyong Xi, who wasn't involved with the project but has long studied how Wolbachia can turn mosquitoes against themselves.

    More research is needed, specialists cautioned. "The results are pretty exciting — strong levels of reductions — but there clearly are going to be things to be learned from the areas where the reductions are not as great," said Penn State University professor Elizabeth McGraw.

Each day, 10-year-old Seth asked his mom for more and more lunch money. Yet he seemed skinnier than ever and came home from school hungry. It turned out that Seth was handing his lunch money to fifth grader, who was threatening to beat him up if he didn't pay.

Most kids have been made fun of by a brother or a friend at some point. And it's not usually harmful when done in a playful and friendly way, and both kids find it funny. But when teasing becomes hurtful, unkind, and constant, it crosses the line into bullying and needs to be stopped.

Bullying is intentional torment(折磨)in physical or psychological ways. It can range from hitting, name-calling and threats to blackmailing(勒索)money and possessions. Some kids bully others by deliberately separating them and spreading rumours about them. Others use social media or electronic messaging to make fun of others or hurt their feelings.

It's important to take bullying seriously and not just brush it off as something that kids have to tolerate. The effects can be serious and affect kids' sense of safety and self-worth. In severe cases, bullying has contributed to tragedies, such as suicides and school shootings.

Kids bully for a variety of reasons. Sometimes they pick on kids because they need a victim—someone who seems emotionally or physically weaker, or just acts or appears different in some way—to feel more important, popular, or in control. Although some bullies are bigger or stronger than their victims, that's not always the case.

Sometimes kids bully others because that's the way they've been treated. They may think their behavior is normal because they come from families or other settings where everyone regularly gets angry and shouts or calls each other names.

Unless your child tells you about bullying—or has visible injuries—it can be difficult to figure out if its happening.