Johnny Smith was a good math student at a high school. He loved his computer. He came home early every day, then he worked with it till midnight. But Johnny was not a good English student, not good at all. He got an F in his English class. One day after school Johnny joined his computer to the computer in his high school office. The school office computer had the grades of all the students: the math grades, the science grades, the grades in arts and music, and the grades in English. He found his English grade. An F! Johnny changed his English grade from an F to A. Johnny' parents looked at his report card. They were very happy.

    "An A in English!" said Johnny's Dad. "You're a very clever boy, Johnny."

    Johnny is a hacker (黑客). Hackers know how to take informationfrom other computers and put new information in. Using a modem, they join their computers to other computers secretly. School headmasters and teachers are worried about hackers. So are the police, for some people even take money from bank computer accountand put it into their own ones. And they never have to leave home to do it! They are called hackers.

    The health of millions could be at risk because supplies of medicinal plants are being used up. These plants are used to make traditional medicine, including drugs to fight cancer. “The loss of medicinal plants is a quiet disaster,” says Sara Oldfield, secretary general of the NGO Botanic Gardens Conservation International.

    Most people worldwide rely on herbal (药草制的) medicines which are got mostly from wild plants. But some 15,000 of the 50,000 medicinal species are under threat of dying out, according to report from the international conservation group Plantlife. Shortages have been reported in China, India, Kenya, Nepal, Tanzania and Uganda.

    Over-harvesting does the most harm, though pollution and competition from invasive species (入侵物种) and habitat destruction all contribute. Businessmen generally harvest medicinal plants, not caring about sustainability (可持续性),” the Plantlife report says, “damage is serious partly because they have no idea about it. but it is mainly because such collection is unorganized” Medicinal trees at risk include the Himalayan yew (紫衫) and the African cherry, which are used to treat some cancers.

    The solution, says the report's author, Alan Hamilton, is to encourage local people to protect these plants. Ten projects studied by Plantlife in India, Pakistan, China, Nepal, Uganda and Kenya showed this method can succeed. In Uganda, the project has kept a sustainable supply of low-cost cancer treatments, and in China a public-run medicinal plant project has been created for the first time.”

    “Improving health, earning an income and keeping cultural traditions are important in encouraging people to protect medicinal plants,” says Hamilton, “You have to pay attention to what people are interested in.”

    Ghillean Prance, the former director of the Royal Botanic Gardens at Kew in London, agrees that medicinal plants are in need of protection. “Not nearly enough is being done,” he told New Scientist. “We are destroying the very plants that are of most use to us.”

    It may sound strange, but cutting down a real tree for Christmas is actually greener than going with the artificial kind, one scientist says.

    “It is a little confusing to people,” said Clint Springer, a biologist at Saint Joseph's University in Philadelphia. Because of concerns over deforestation（砍伐森林）around the world, many people naturally worry that buying a real tree might contribute to that problem. But most Christmas trees for sale these days are grown not in the forest but on tree farms for the purpose of being cut.

    Moreover, from the viewpoint of greenhouse gases, real trees are “the obvious choice”. Live trees actively release oxygen as they grow, and meanwhile remove carbon dioxide from the atmosphere. After they have been cut and Christmas is over, they're usually cut into smaller pieces for mulch（覆盖物）. As mulch, the bits of trees very slowly release carbon dioxide back into the atmosphere. So in the end, a real Christmas tree is carbon neutral, putting the same amount of carbon dioxide back into the air as it took out (although much more slowly).

    The tree farms that grow the trees also replant after the trees are cut.  Artificial trees, on the other hand, don't come out even in the carbon balance. Petroleum（石油）is used to make the plastics in artificial trees and lots of carbon dioxide-creating energy is required to make and transport them. Because these trees just end up in the places where waste is buried under the ground after use, “those greenhouse gases are lost forever,” Springer said.

    An old friend from California called from the airport to tell me that he had arrived. I was not able to leave the office, but I had made plans for his arrival. After explaining (解释) where my new house was, I told him that I had left the key under the doormat (门垫). Since I knew it would be pretty late before I could get home, I suggested that he make himself at home and help himself to anything that was in the refrigerator(电冰箱).

    Two hours later my friend phoned me from the house. At the moment, he said, he was listening to some of my records after having had a delicious meal. Now, he said, he was drinking a glass of orange juice. When I asked him if he had had any difficulty finding the house, he answered that the only problem was that he had not been able to find the key under the doormat, but luckily, the living room window by the apple tree had been left open and he had climbed in through the window. I listened to all this in great surprise. There is no apple tree outside my window, but there is one by the living room window of my next door neighbor's house!

    Australia was first used as an island prison by Britain to solve their problem of having a fast growing prison population. These early settlers were those who were sent from all over Great Britain, including Ireland, Wales, and Scotland. Later events, such as the gold rush, caused several waves of immigration (移居) from Europe, Asia and other parts of the world. It is commonly thought that Australians are offspring (后代) of those criminals (罪犯)! In fact, only a part of Australians are those criminals' offspring. Also, in those days, people could be put into prison or sent to Australia for small crimes, like stealing a loaf of bread. Today Australia is home to the largest Greek and Italian communities in the world, outside Greece and Italy. This has helped the Australian accent develop.

    Australian English was created by the first generation of children born in the new area. Since they talked with people who have different accents, they began to speak a distinct dialect of English that was to become the language of the nation. These differences were first noted by late arrivals in the early 1800s, and the language sounds like Cockney English, spoken by the working­class in London.

    Soon, words from native languages were to become part of the Australian English. Here are some words you may consider them to be Standard English. In fact, they are from native Australian languages!

    The names of many places and animals, including Canberra (the Australian capital, meaning "meeting place" in a local language).

    Hard yakka — meaning "hard work", coming from the language of the Brisbane area.

    Cooee — a call used traditionally by native Australians to attract attention, because the sound can travel long distances.

    Bung — meaning "dead", but also used to mean broken or useless, for example, "He has a bung eye".

Cattle manure(粪肥) has become one of the world's greatest environmental killers, but one Dutch artist is using chemistry to turn it into something that is both eco-friendly and valuable.

In recent years, scientists around the world have made great progress in their attempts to recycle cattle manure, including turning it into natural fertilizer, but Eindhoven designer Jalila Essaidi didn't think they were efficient enough to solve the global manure problem. So she started on her very own solution, one that approached animal waste as a valuable material that could be processed into useful products.

She started by separating the waste, with the dry manure used to get pure cellulose(纤维素) from the grass that cows eat. From the wet manure, she got acids used to create a natural liquid plastic which was used to make fiber that are later turned into fabric(material used for making clothes).

This new material was named Mestic, from mest, the Dutch word for manure. Essaidi claim that it has the same function as plastic from fossil fuels, but is bio-degradable(可生物降解的). Better yet, the degradability can be dealt with in the lab, making it possible to create materials that last for different periods of time depending on their purpose. "This is not the first time that scientists have been looking for ways to solve the manure problem, but it is the first time that manure is being considered as a valuable resource." the Dutch designer said.

Last year, Jalila Essaldi partnered with the city of Eindhoven to produce a fashion show using Mestic-based fabrics. Her Mestic collection was so impressive that clothing giant H&M awarded her the Global Change Award and a $1million prize. And cow manure is just the beginning of Jalila Essaldi's experiments with animal waste. "After cows, we'll deal with pigs and other animals," she said.