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.

    Located in Los Angeles, University of Southern California is in the heart of a leading city. Although LA ranks highly in The Economist s Safe Cities Index, navigating and city calls for certain safety precautions (预防措施) along with practicing common sense.

    Mobile Safety App Powered by LiveSafe

    The Mobile Safety App powered by LiveSafe, manage by the USC Department of Public Safety and the USC Department of Emergency Planning, is a free downloadable app that that mobile users can use to initiate contact with emergency responders around the campus. Features include: immediate “push button” calls to DPS, easy reporting for suspicious activity or crimes in progress, and location services to notify friends of your route through campus.

    Blue Light Phone Locations

    The University Park has multiple blue light phones that are strategically placed throughout campus. Take note of where the closest ones are on your route. They come in handy in case you lose your phone or in an emergency. These phones are directly connected to USC's Department of Public Safety's 24-hour communications center. Besides emergency needs, it can also be used to report suspicious activity, request for an escort (护送) if you feel unsafe and to report a crime.

    Trojans Alert

    Trojans Alert is an emergency notification system that allows university officials to contact you during an emergency by sending messages via text message or email. When an emergency occurs, authorized USC senders will instantly notify you with real-time updates, instructions on where to go, what to do (or what not to do), whom to contact and other important information. All members of the USC community, as well as parents and regular visitors to campus, are strongly encouraged to sign up for Trojans Alert.

    I was 16 when my father finally decided he would send me to wilderness camp for several months. He had threatened to do it many times before, but my mother had always managed to prevent him from doing so. This ti me he insisted on doing it.

    The latest incident was the last straw. Impulsively (冲动地), I had pushed Mr. Ford, my math teacher, down a flight of steps at school. He broke his arm in two places. Anyway, he had agreed not to accuse me as a favor to my dad, who was in the middle of a tight race for sheriff (执法官) in our town. But my reckless behavior had my dad's closest advisor talking.

    "John, he's your son and he's a kid, but he is dragging you down," I heard Jake Hutch tell my dad through his closed office door the night after I pushed Mr. Ford. "If you can't make your son obey the rules, how can you make the law obeyed in this town?"

    So, off to Pisgah National Forest I went. I imagined hours of untold abuse at the hands of some strong sergeants (军士). I was determined not to be broken. I was who I was,

    Nearly every day for six months, a small group of other troubled teens and I carried our 30-pound backpacks on a difficult journey covering about 10 miles. We hiked in a rough wilderness that seemed untouched by civilization.

    Our sergeants were firm but kind, not frightening as I had imagined. We learned how to make a fire without matches and create a shelter with branches and grass. We learned which plants were safe to eat out in the wild. I felt myself change. I was calm and often reflective. My old, impulsive self was gone.

    One morning, six months later, my dad came to pick me up. I ran to hug him and saw happiness and love in his eyes.

    "So what's it like being sheriff?" I asked on the ride home.

    "I lost the race, Danny," he said.

    "I'm sorry, Dad." I knew my behavior probably had a lot to do with the defeat.

    Dad squeezed my shoulder and brought me close. "As long as I don't ever lose you, I'm okay."

    HANGZHOU — Chinese internet giant Alibaba on Tuesday opened a hotel loaded with artificial intelligence (AI) and robots, automating a series of procedures like check­ in, lights control and room service.

    FlyZoo Hotel, opened in Hangzhou, capital of East China's Zhejiang province, where Alibaba is headquartered, is known as the company's "first future hotel". Customers can check into the hotel by simply scanning their faces. The facial recognition system installed in the hotel also enables customers to use their faces as key cards to open doors and access another hotel service. Users can also control the lights, televisions and curtains in the room via Alibaba's voice­activated digital assistant, while robots are deployed to serve dishes, cocktails and coffee. Hotel bookings and check­out can also be done with a few clicks on mobile through an app. "The AI­based solution can help customers save time and relieve hotel employees from repetitive work," said Wang Qun, CEO of FlyZoo Hotel. The hotel is the latest example of Chinese tech companies' attempt into traditional industries such as the hotel industry.

    E­commerce giant JD.com announced in October its strategy to put smart home and electronic devices sold on its platform into hotels, in an effort to improve online sales.

    In July, Baidu teamed up with Intercontinental Hotels Group in Beijing to allow guests to use its voice­ controlled assistant to adjust room temperature and order room service at ease.

    Before that, social media giant Tencent introduced QQfamily, a similar tech solution for hotel operators, in the southern city of Zhuhai last year.

    "We want to install a 'smart brain' for hotels," said Wang. "In the future, we will continue to make hotels smarter and more automated, as well as create more personalized experiences for consumers."

    When it comes to learning a foreign language, many people wonder if they will be able to memorize enough vocabulary. But this question never happens about their mother tongue, and yet, it was a foreign language once. However, among all the questions that new parents ask, no doctor has ever heard: "Will my baby be able to learn my language?" Be honest, do you know all the words of your mother tongue? The answer is: "no".

    New words, and new ways of using old words, appear every day. Twenty years ago, who could have been able to understand a sentence like this: "Click here to download your digital book."? Nobody. You never stop learning new vocabulary and you never know how long you will need it.

    Sometimes, you have the word on the tip of your tongue...and it sticks there! But you do know this phenomenon(现象) and don't think that it is because of a bad memory. You should not give this phenomenon more importance in the language you are learning than in your mother tongue.

    You need to learn only 2000 or so basic words to be able to create any phrase you need. You can't avoid some work in order to learn these necessary words and all the more if you want to learn quickly. And before you consider buying into any method, be sure it is right for you. It is not wise to depend on any method based upon mnemonics(记忆群). The first few words seem very easy to learn, so you buy the course, but then you discover quickly, though too late, that a dozen words later, it is all the more difficult to learn a new word when you have also to learn the trick to memorize it.

Two men were sitting together in a plane. They were on a long journey. One of the men was a businessman. The other was a farmer. They sat without talking for a while, then the farmer said, "Let's do something to pass the time."

"What do you want to do?" the businessman asked. "We can ask each other riddles(谜语）." The farmer said, "You start." "Let's make the rules first," the businessman said. "That's not fair. You are a businessman with much knowledge. You know more things than I do. I am just a farmer."

"That's true." The businessman said. "What do you want we should do?" "If you don't know the answer to a riddle, you pay me $100. And if I don't know the answer, I'll pay you $50." The farmer said. The businessman thought about this, then he said, "OK. That's fair. Who will go first?"

"I will," The farmer said. "Here is my riddle. What has three legs when it walks, but only two legs when it flies?" The business man repeated the riddle, "What has three legs when it walks, but only two legs when it flies? Mm, that's a good one. I'm afraid I don't know the answer." He gave the farmer $100, then said, "Tell me the answer. What has three legs when it walks, but only two legs when it flies?" "I don't know." The farmer said and gave him $50.