These days a green building means more than just the color of the paint. Green buildings can also refer to environmentally friendly houses，factories，and offices.

    Green building means "reducing the effect of the building on the land"，Taryn Holowka of the US Green Building Council (评议会) in Washington，D.C.，said. According to Holowka，building accounts for 65 percent of total US electricity use.

But green buildings can reduce energy and water use. Also，the buildings are often located near public transportation such as buses and subways，so that people can drive their cars less. That could be good for the environment，because cars use lots of gas and give off pollution. Green buildings are often built on developed land，so that the buildings don't destroy forests.

    Marty Dettling is project manager for a building that puts these ideas into action. The Solaire has been called the country's first green high-rise building. According to Dettling，"We've reduced our energy use by one-third and our water by 50 percent."

    The Solaire cuts energy in part by using solar power. "On the face of the building we have solar panels (光板) which change the sun's energy into electricity，" Dettling explained.

    The Solaire also has lights that automatically turn off when people leave the room. In addition，the building has lots of windows，allowing people to use the sun for light during the day. The Solaire cuts water by reusing it.

    Not everyone is eager to move into a green building，however. Some people think that things like solar panels cost more money than more traditional energy sources. Anyhow，Holowka said，"It's going to be big."

    Metal-organic frameworks(MOFs) are compounds that are set to solve some tough challenges: producing water in the desert, removing greenhouse gases from the air and storing dangerous gases more safely.

    The Arizona desert is really dry. Anyone stuck in it without water would die from dehydration (脱水) within three days. Unless, that is, they had one of Omar Yaghi's next-generation water harvesters. Although daytime humidity(湿度)is only about 10 per cent, this rises to 40 per cent at night, which means there's enough water in the atmosphere to support life — if it can be transformed into liquid form.

    That's exactly what Yaghi's device does. It's a box about the size of a small microwave oven designed to suck the humidity from the air at night and turn it into drinking water the next day using only the heat of the sun as its power source. What makes it work is a special material called a metal-organic framework (MOF), which at normal temperatures attracts water molecules (分子) onto its surface of its internal pores(细孔). Warm it up and the water is released, each harvest producing one-third of a cup of pure drinking water.

    "With further improvements, a device, the size of a washing machine, could produce enough water for the basic needs of a household," says Yaghi, a chemist at the University of California. One-third of the world's population lacks safe drinking water; for them such a device could be a lifesaver.

    These crystalline cluster(结晶群)of metals, such as aluminum or magnesium, linked by organic molecules can be made into materials with an extremely high absorption ability, attracting specific molecules to their surface. In this way, MOFs cling to a variety of liquids and gases.

MOFs work thanks to their unique structure—large quantities of nanometer-sized internal spaces. In fact one MOF has so many pores that they would cover an area as large as six football fields. MOFs are also extremely stable light and have many different uses: their molecular structure can be varied to attract specific molecules, such as water, and their pores can be designed to best store them. Adding a small amount of heat or pressure causes the MOF to release what it is holding. More than 70,000 different MOFs have been produced to date for various applications.

    Supermarket shoppers who buy lots of foods on "two for one" deals are far more likely to be obese (肥胖的), a major study suggests.

    Cancer Research UK found that those with highest consumption of discounted foods were at 50 percent greater risk of obesity, compared with those with low take-up of such deals.

    The study of more than 16,000 households found almost one in three food and drink items in UK supermarket baskets were bought on promotion. And the discounts were far more likely to be applied to unhealthy foods, with almost half of all chocolate, crisps, popcorn, and savoury snacks bought on promotion.

    Shoppers whose baskets contained between 40 and 80 percent of goods on special offer were 54 percent more likely to be obese than those with a maximum 20 percent of foods on such deals. Those with highest take-up of the deals bought 30 percent less fruit, and nearly 25 percent fewer vegetables than those shunning the deals.

    The study follows a government consultation on proposals to ban "buy one, get one free" deals on unhealthy foods and supermarket "guilt lanes" as part of its childhood obesity strategy.

    One in five children are overweight or obese when they start primary school, rising to around one in three when they leave.

    Research has found that obesity increases the risk of 13 different types of cancer including bowel and breast disease.

    Alison Cox, director of cancer prevention at Cancer Research UK, said: "The government's proposed 9 p. m. ban on junk food ads is a step forward in fighting childhood obesity. Now we want to see restrictions on price promotions for unhealthy food and drink items, as well as those strategically placed at checkouts. This will help families to make healthier choices.

    "There isn't one magic fix for the problem, but getting rid of these encouragements to buy unhealthy food is key to changing it."

    The values of artistic works, according to cultural relativism (相对主义), are simply reflections of local social and economic conditions. Such a view, however, fails to explain the ability of some works of art to excite the human mind across cultures and through centuries.

    History has witnessed the endless productions of Shakespearean plays in every major language of the world. It is never rare to find that Mozart packs Japanese concert halls, as Japanese painter Hiroshige does Paris galleries, Unique works of this kind are different from today's popular art, even if they began as works of popular art. They have set themselves apart in their timeless appeal and will probably be enjoyed for centuries into the future.

    In a 1757 essay, the philosopher David Hume argued that because "the general principles of taste are uniform (不变的) in human nature," the value of some works of art might be essentially permanent. He observed that Homer was still admired after two thousand years. Works of this type, he believed, spoke to deep and unvarying features of human nature and could continue to exist over centuries.

    Now researchers are applying scientific methods to the study of the universality of art. For example, evolutionary psychology is being used by literary scholars to explain the long-lasting themes and plot devices in fiction. The structures of musical pieces are now open to experimental analysis as never before. Research findings seem to indicate that the creation by a great artist is as permanent an achievement as the discovery by a great scientist.

    If you are a teenager without a job, you probably do not have much extra money. Sometimes parents will give their children a pocket money for doing small housework, but it is often not enough once the children grow into teenagers and want to do things with their friends all of the time. How to make money is an important thing for teens to learn. If you're wondering how a teenager can make good money, some ideas might be:

    Getting a part-time job at a local restaurant or store is always a sure way to make money as a teen. But getting a job somewhere like this might be hard, considering many jobs in local stores are being taken by adults more and more often.

    Doing landscaping (绿化) is something that most adults do not like to do, and teens can usually find jobs around their neighborhood doing the landscaping of friends and family.

    Some teens are good at something such as writing or photography. These teens can make money by doing things such as writing articles for newspapers or magazines or selling their photos online.

    Teens who live in a country area can earn money by helping out on farms, or they can try raising their own animals such as chickens, and selling them or their products.

    Looking for jobs can seem hard at first, but if you have a try, it should not be too hard to find a job or way to make money.

Workers are returning to their careers, or starting new ones after age 65.

More than ever, work is where many of us get our sense of purpose. That doesn't end at age 65. After being retired for only three months, Sue Ellen King returned to work at the University of Florida Health in Jacksonville, Florida, where she had been a care nurse and nursing educator for 38 years. She is now working part-time in a position created just for her. "It's perfect," she told The New York Times. "I get the satisfaction of having people appreciate what I do." With the average lifespan for those who reach age 64 now getting all the way to 84 years old, those who reach retirement age still have many potential years of work to go.

Job sites connected toward part-timers, temporary positions, and some can also turn up opportunities that may lead to longer-term work. Fred Dodd tried a part-time job after his unemployment as a clerk for large banks at age 63. He'd thought about retiring then. "But part of me just wanted to keep working partly for the money, but more just because I felt I wanted to do more in my career, " he said.

The retired have the advantage of not needing to focus on the earnings potential of whatever jobs they take on, so these older workers are attracted to more meaningful work. And since they are voluntarily putting their skills and experience to good use, they may well have more flexibility than mid-career people. Two-thirds of retirees who'd come back to the work world were doing meaningful work they enjoyed. Legal work and community service were popular choices, as was teaching—all areas in which older workers might have an opportunity to make their own schedules.

Earning more money rarely seems like a bad idea, but it can cause issues for retirees, including effects when they claim Social Security (申请社会保障) benefits early.