【推荐2】Scientists have been studying how people use money for long. Now they’re finding some theories may apply to one group of monkeys.

Researchers recently taught six monkeys hos to use money. They gave the monkeys small metal disks (圆片) that could be used like cash and showed them some yummy apple pieces. The monkeys soon figured out that if tyey gave one of the disks to a scientist, they’d receive a piece of apple in return.

If you think that is all the monkeys can figure out, you are wrong. Two researchers, Jake and Allison, acted as apple sellers in the experiments. The monkeys were tested one at a time and had 12 disks to spend in each experiment. Jake always showed the monkeys on apple piece, while Allison always showed two pieces. But that’s not necessarily what they gave the monkeys. The number of apple pieces given for a disk was determined at random.

Experiment One: Allison showed two pieces of apples but gave both piece only half the time. The other half, she took one piece away and gave the monkey just the remaining piece. Jake, on the other hand, always gave exactly what he showed: one piece for each disk. The monkeys chose to trade more with Allison.

Experiment Two: Allison continued to sometimes gave two pieces and sometimes one piece. But now, half the time, Jake gave the one apple piece he was showing, and half the time he added a bonus. Guess what? The monkeys chose to trade more with Jake.

In the first experiment, the monkeys correctly figured out that if they traded with Allison, they’d end up with more treats. In the second one, when a monkey received two pieces from Jake, it seemed like a gain. When Allison gave the monkey only one piece instead of the two she showed, it seemed like a loss. The monkeys preferred trading with Jake because they’d rather take a chance of seeming to win than seeming to lose.

We also sometimes make silly business decisions just to avoid the feeling that we’re getting less, even when we’re not. Would you have made the same choices?

【推荐3】People and other great apes are known for their willingness to help others in need, even strangers. Now, researchers have shown for the first time that some birds-specifically African grey parrots-are similarly helpful.

"We found that African grey parrots voluntarily help familiar parrots to achieve a goal, without obvious immediate benefit to themselves," says Desiree Brucks of the Max Planck Institute for Birds Study, Germany.

Parrots and crows are known for having large brains relative to the size of their bodies and problem-solving skills to match. For that reason, they are sometimes considered to be“feathered apes," explains Brucks. However, earlier studies showed that, despite(尽管)their impressive social intelligence, crows don't help other crows. In their new study, Brucks and his fellows wondered: what about parrots?

To find out, they placed pairs of grey parrots and blue-headed parrots in boxes alongside each other with a transfer(转移)hole between the two, and a hole facing a human experimenter that was either kept open or closed. Both parrot species quickly learned that they could exchange tokens(筹码)with the experimenter for a nut treat-but only the grey parrots helped their neighbors when their own hole facing the scientist was closed, preventing them from gaining any personal reward.

In the very first round, seven out of eight grey parrots were willing to transfer tokens in their possession to their neighbors so that their friends could feast when they could not. The fact that they did so without knowing they would later be tested in the other role showed that those giving were not expecting the favor to be rewarded, said Brucks.

Significantly, the grey parrots appeared to understand the nature of the task, instead of acting out of playfulness. When they saw the other parrot had an opportunity for exchange, they'd pass a token over-but otherwise, they would not. And, like humans, the grey parrots appeared to favor their friends, sharing more tokens with birds they had previously closely associated with, though they still gave some to those they are familiar with.

【推荐2】Music is an international language. The songs that are sung or played by instruments are beautiful to all people everywhere.

Popular music in America is what every student likes. Students carry small radios with earphones and listen to music before class, after class, and at lunch. Students with cars buy large speakers and play the music loudly as they drive on the streets.

Adult drivers listen to music on the car radio as they drive to work. They also listen to the news about sports, the weather, politics, and activities of the American people. Most of the radio broadcast is music.

Pop or popular music singers make much money. They make a CD or tape which radio stations use in every state. Once the pop singer is heard throughout the country, young people buy his or her tapes. Some of the money from these tapes comes to the singer. Wherever the singer goes, all the young people want to meet him or her. Now the singer has become a national star.

There are other kinds of music that are important to Americans. One is called folk music. It tells stories about the common life of Americans. Another is called western or country music. This was started by cowboys who would sing at night to the cows they were watching. Today, any music about country life and the love between a country boy and his girl is called western or country music.

Serious music for the concert halls is called classical music. Music for instrument is called orchestra music (管弦乐),such as the symphonies (交响乐) of Beethoven. There is opera (歌剧 ) for singers. There is ballet for dancers like Liang Shanbo and Zhu Yingtai in China.

【推荐3】Smokers may ignore the health warnings by telling themselves their habit makes them look cool. After all, sex symbols James Dean and Humphrey Bogart were rarely seen without a cigarette. However, the latest evidence shows that smoking actually makes you less attractive to the opposite sex. Wrinkles from smoking a cigarette may be to blame for people judging non-smokers to be better-looking.

This was the result of a study asking more than 500 people to pick the most attractive of twins where one smoked and the other did not. Men found female non-smokers the most attractive in two-thirds of cases, while women chose non-smoking men as the most attractive 68 percent of the time.

Professor Ian Penton-Voak, a co-author of the study from Bristol University, said, “People assume that smoking causes damage to the skin and appearance, but this is a really neat way of looking at it because these twins are genetically identical, so we can control for genetic factors involved in ageing. Appearance seems to be important to people, especially young people, so we could use these sorts of findings as a basis for future interventions to stop people smoking.”

Smoking can speed up the normal ageing, even after only a decade. Nicotine causes narrowing of the blood vessels in the outermost layers of the skin, while the chemicals in tobacco smoke damage collagen and elastin, fibres which give the skin its elasticity(弹性).

The wrinkles this causes are added to by facial expressions made when smoking—such as pursing the lips when inhaling(吸气)or squinting to keep smoke out of your eyes.