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.

    The Renaissance，considered by modern scholars to have been the time between 1,300 and 1,600，was a period of European history when many new inventions and beliefs came into being.

    The Renaissance is traced back to rich Italian cities such as Florence，Milan，and Venice.In these cities businessmen started to spend their extra money on things like painting and education，and to consider new techniques of banking and systems of government.A new type of scholar，the humanist(人文主义者)arose.Humanism was concerned with humankind and culture.Latin and Greek，literature and philosophy，music and mathematics were among the subjects humanists studied.

    The Renaissance gave rise to new forms of painting and  sculpture.During  the  Renaissance，artists were no longer regarded as mere artisans(工匠)．Many artists drew on mathematics in order to become more accurate in their measurements(度量)and to make sure an object was presented in realistic proportions.They also studied the way light hits objects and the ways our eyes perceive it.A new kind of paint，called oil paint，was invented.

    The Renaissance affected all of the society.Many people became interested in politics，and the world outside their towns.They became explorers，businessmen，etc.The effect on religion was especially strong.In the Middle Ages people were primarily concerned with serving the church and getting to heaven.But the increase in arts  and education gave  people things to look forward to in life，and made them lose interest in the church.

    The  Renaissance  produced  many  great minds.Leonardo da Vinci was one of the greatest，although he was not regarded that way at the time.Among his many works of art were Mona Lisa and The Last Supper.He is also regarded as a great inventor，and is credited for coming up with the idea of the helicopter.

I'm part of the Roots & Shoots program founded by Dr. Jane Goodall. The program is intended to make and promote positive changes in the world. As Dr. Goodall says, "What you do makes a difference, and you have to decide what kind of difference you want to make."

    In Bulgaria, where I live, homeless dogs are everywhere. Many people here turn a blind eye to them. But I cannot ignore the life of a street dog whenever I see one wandering in the street, looking for something to eat. That's why I'm no longer a food waster. When I see wasted food, I always think of a hungry dog climbing to garbage bins, searching for food that people have thrown there. When eating in a restaurant, I'm not afraid to take leftover food to feed stray cats or dogs.

    A week ago, I saw a homeless dog around the garbage bins. Immediately I knelt down, spoke to her softly and ran my hands over her. I could see that she had had puppies. I couldn't imagine how she could have been able to care for them. Hours earlier, I'd bagged up a plate of leftover fish. As I unwrapped it, she wagged her tail and sniffed at it. She ate all the fish in no time.

    It's sad, isn't it? I can't understand why many of us waste so much and think little of it. These homeless animals have taught me that food is precious. Even when I don't have leftovers with me, I'll take the time to get something from the grocery store to feed them.

I know my power is small, so I hope that next time you see wasted food, do turn it into worthy food. You have the power to save a life!

    Tim Richter and his wife, Linda, had taught for over 30 years near Buffalo, New York – he in computers, she in special education. "Teaching means everything to us," Tim would say. In April 1998, he learned he would need a heart operation. It was the kind of news that leads to some serious thinking about life's purpose.

    Not long after the surgery, Tim saw a brochure describing Imagination Library, a program started by Dolly Parton's foundation (基金会) that mailed a book every month to children from birth to age five in the singer's hometown of Sevier, Tennessee. "I thought, maybe Linda and I could do something like this when we retire," Tim recalls. He placed the brochure on his desk, "as a reminder."

    Five years later, now retired and with that brochure still on the desk, Tim clicked on imaginationlibrary.com. The program had been opened up to partners who could take advantage of book and postage discounts.

    The quality of the books was of great concern to the Richters. Rather than sign up online, they went to Dollywood for a look-see. "We didn't want to give the children rubbish," says Linda. The books – reviewed each year by teachers, literacy specialists and Dollywood board members – included classics such as Ezra Jack Keats's The Snowy Day and newer books like Anna Dewdney's Llama Llamaseries.

    Satisfied, the couple set up the Richter Family Foundation and got to work. Since 2004, they have shipped more than 12,200 books to preschoolers in their area. Megan Williams, a mother of four, is more than grateful: "This program introduces us to books I've never heard of."

    The Richters spend about ＄400 a month sending books to 200 children. "Some people sit there and wait to die," says Tim. "Others get as busy as they can in the time they have left."

    Teachers' Day is, interestingly, not celebrated on the same day all over the world. In some countries it is marked by a holiday; in others it is a working day.

    International Teachers' Day is celebrated on October 5. Being held ever since 1994, it is in honor of teachers' organizations worldwide. Its aim is to encourage supports for teachers and to meet the needs of students.

China — In 1939, Teachers' Day was set for August 27, Confucius' birthday. In 1951, the celebration was stopped. However, it was founded again in 1985, and the day was changed to September 10.

India — Teachers' Day is celebrated on September 5 in honor of Dr. Sarvepalli Radhakrishnan, the second president of India, whose birthday falls on that day.

    Russia — In Russia, Teachers' Day was celebrated on the first Sunday of October between 1965 and 1994. Since 1994, the day is observed on October 5, just the same day as World Teachers' Day.

    The US - In the US, Teachers' Day is non-official holiday. It is celebrated on the Tuesday of the first full week of May. A number of activities are organized in schools to honor teachers. The celebrations can continue for the whole week of May.

Thailand — In Thailand, National Teachers' Day is celebrated every year on January 16. The first Teachers' Day was held in 1957. The day is a holiday in schools.

    It was only -28℃ when we landed in Siberia. That was cold enough to make breathing difficult. Five minutes later, I asked for a second pair of gloves and pulled my scarf tight over my nose and mouth. Clearly, I was a complete beginner to this. At the bus station, Mikhail laughed when we asked him why he wasn't freezing. He had spent the whole day outside only with his fur hat and a sheepskin coat for warmth. It was mid-afternoon and icicles（冰柱）were hanging from his beard.

    In Siberia, there's a belief that enough vodka（伏特加酒）will save you from the cold. However, it's wrong. The local hospital is crowded. Even here, icicles are hanging down on the inside of the windows, though the heating is at full power. The doctors are too busy to talk to us.

    The winter here is cruel —and this one is especially so. After her work as a teacher, Natasha Fillipova comes home. It is a freezing house. She shows us the bedroom — where ice has built up on the inside walls. One night, Natasha washed her hair before going to bed. When she woke up, it was frozen hard to the wall. Now the children are doing their homework in the bathroom — the only room warm enough to sit in. Natasha doesn't want to complain. But she is angry with the government and the architects for building terrible houses.

    The houses here are supposed to stand up to -40℃, but they don't. And her children are ill with coughs and colds. Of course, Natasha's anger is brief, and she seems embarrassed about it. According to her, Siberians are used to the cold weather. People here prefer to depend on themselves and the knowledge that spring will come in the end.