Along the river banks of the Amazon and the Orinoco there lives a bird that swims before it can fly, flies like a fat chicken, eats green leaves, has the stomach of a cow and has claws(爪)on its wings when young .They build their homes about 4.6m above the river ,an important feature(特征)for the safety of the young. It is called the hoatzin.

    In appearance, the birds of both sexes look very much alike with brown on the back and cream and red on the underside .The head is small, with a large set of feathers on the top, bright red eyes, and blue skin. Its nearest relatives are the common birds, cuckoos. Its most striking feature, though, is only found in the young.

    Baby hoatzins have a claw on the leading edge of each wing and another at the end of each wing tip .Using these four claws ,together with the beak(喙),they can climb about in the bushes, looking very much like primitive birds must have done. When the young hoatzins have learned to fly, they lose their claws.

    During the drier months between December and March hoatzins fly about the forest in groups of 20 to 30 birds, but in April, when the rainy season begins, they collect together in smaller living units of two to seven birds for producing purposes.

    Such chronic (慢性的) diseases as heart disease, stroke, cancer and lung disorders are the most leading causes of death in the world. Yet health experts say these conditions are often the most preventable.

    The World Health Organization (WHO) points out chronic diseases lead to about 17 million early deaths each year. The United Nations (UN) agency expects more than 380 million people to die of chronic diseases by 2015. About 80% of the deaths will happen in developing nations.

    Chronic diseases now cause two-thirds of all deaths in the Asia-Pacific area. In ten years it could be almost three-fourths. People are getting sick in their most economically productive years. In fact, chronic diseases are killing more middle-aged people in poorer countries than in richer ones. The WHO estimates (估计) that chronic diseases will cost China alone more than 500,000 million dollars in the next ten years. That estimate represents the costs of medical treatment and lost productivity. Russia and India are also expected to face huge economic losses.

    According to a WHO report, deaths from chronic diseases have increased largely as the result of economic gains in many countries. Until recently infectious and parasitic (寄生的) diseases have been the main killers in Asia and the Pacific but they are no longer the major cause of death in most countries.

As many as 80% of the deaths from chronic diseases could be prevented, health officials say. An important tool for governments is to limit the marketing of alcohol and tobacco to young people. Also, more programs are needed to urge healthy eating and more physical activity.

    The UN aims to reduce chronic-disease deaths by 2% each year by international action through 2015, that's to say, 36 million lives could be saved, including 25 million in Asia and the Pacific.

    If you could be anybody in the world, who would it be? Your neighbour or a super star? A few people have experienced what it might be like to step into the skin of another person, thanks to an unusual virtual reality（虚拟现实）device. Rikke Wahl, an actress, model and artist, was one of the participants in a body swapping experiment at the Be Another lab, a project developed by a group of artists based in Barcelona. She swapped with her partner, an actor, using a machine called The Machine to Be Another and temporarily became a man. "As I looked down, I saw my whole body as a man, dressed in my partner's pants," she said. "That's the picture I remember best."

    The set-up is relatively simple. Both users wear a virtual reality headset with a camera on the top. The video from each camera is sent to the other person, so what you see is the exact view of your partner. If she moves her arm, you see it. If you move your arm, she sees it.

    To get used to seeing another person's body without actually having control of it, participants start by raising their arms and legs very slowly, so that the other can follow along. Eventually, this kind of slow synchronised（同步的）movement becomes comfortable, and participants really start to feel as though they are living in another person's body.

    Using such technology promises to alter people's behaviour afterwards-potentially for the better. Studies have shown that virtual reality can be effective in fighting racism-the bias（偏见）that humans have against those who don't look or sound like them. Researchers at the University of Barcelona gave people a questionnaire called the Implicit Association Test, which measures the strength of people's associations between, for instance, black people and adjectives such as good, bad, athletic or awkward. Then they asked them to control the body of a dark skinned digital character using virtual reality glasses, before taking the test again. This time, the participants' bias scores were lower. The idea is that once you've "put yourself in another's shoes" you're less likely to think ill of them, because your brain has internalised the feeling of being that person.

    The creators of The Machine to Be Another hope to achieve a similar result. "At the end of body swapping, people feel like holding each other in their arms," says Arthur Pointeau, a programmer with the project. "It's a really nice way to have this kind of experience. I would really, really recommend it to everyone."

    The fiddler crab (蟹) is a living clock. It indicates the time of day by the colour of its skin, which is dark by day and pale by night. The crabs changing colour follows a regular twenty-four hour plan that exactly matches the daily rhythm (节奏) of the sun.

    Does the crab actually keep time, or does its skin simply answer to the sun's rays, changing colour according to the amount of light strikes it? To find out, biologists kept crabs in a dark room for two months. Even without daylight, the crab's skin colour continued to change exactly on time.

    This characteristic(特性) probably developed gradually in answer to the daily rising and setting of the sun, to help protect the crab from sunlight and enemies. After millions of years it has become completely regulated (受控制) inside the living body of the crab.

    The biologists noticed that once each day the colour of the fiddler crab is especially dark, and that each day this happens fifty minutes later than on the day before. From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides (潮水). The crabs period of greatest darkening is exactly the time of low tide on the beach where it was cought!

Economically speaking, are we better off than we were ten years ago? Twenty years ago?

In their thirst for evidence on this issue, commentators seized on the recent report by the Census Bureau, which found that average household income rose by 5.2% in 2015. Unfortunately, that conclusion puts too much weight on a useful, but flawed and incomplete, statistic. Among the more significant problems with the Census's measure are that: 1) it excludes taxes, transfers, and compensation like employer-provided health insurance; and 2) it is based on surveys rather than data. Even if precisely measured, income data exclude important determinants of economic wellbeing, such as the hours of work needed to earn that income.

While thinking about the question, we came across a recently published article by Charles Jones and Peter Klenow, which proposes an interesting new measure of economic welfare. While by no means perfect, it is considerably more comprehensive than average income, taking into account not only growth in consumption per person but also changes in working time, life expectancy, and inequality. Moreover, it can be used to assess economic performance both across countries and over time.

The Jones-Klenow method can be illustrated by a cross-country example. Suppose we want to compare the economic welfare of citizens of the U.S. and France in 2005.

In 2005, as the authors observe: real consumption per person in France was only 60% as high as the U.S., making it appear that Americans were economically much better off than the French on average. However, that comparison omits other relevant factors: leisure time, life expectancy, and economic inequality. The French take longer vacations and retire earlier, so typically work fewer hours; they enjoy a higher life expectancy, presumably reflecting advantages with respect to health care, diet, lifestyle, and the like; and income and consumption are somewhat more equally distributed there than in the U.S. Because of these differences, comparing France's consumption with the U.S.'s overstates the gap in economic welfare.

Similar calculations can be used to compare the U.S. and other countries. For example, this calculation puts economic welfare in the United Kingdom at 97 % of U.S. levels, but estimates Mexican well-being at 22%. The Jones-Klenow measure can also assess an economy's performance over time. According to this measure, as of the early-to-mid-2000s, the U.S. had the highest economic welfare of any large country. Since 2007, economic welfare in the U.S. has continued to improve. However, the pace of improvement has slowed markedly.

Methodologically, the lesson from the Jones-Klenow research is that economic welfare is multi-dimensional. Their approach is flexible enough that in principle other important quality-of-life changes could be incorporated—for example, decreases in total emissions of pollutants and declines in crime rates.

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The oldest bamboo {#blank#}3{#/blank#}(article) in China were unearthed from the remains of a primitive society that existed some 7,000 years ago in {#blank#}4{#/blank#}is now Hemudu,Yuyao County, Zhejiang Province. As early as the Shang Dynasty, Chinese people used the bamboo for making weapons, such as bows and arrows. Before paper {#blank#}5{#/blank#}(invent), strips of bamboo were the most important writing medium, more widely used than silk, {#blank#}6{#/blank#}they were cheaper, resistant to corrosion(腐蚀) and more abundant. Bamboo has thus played an important part in the spread and development of traditional Chinese culture. 

Bamboo was {#blank#}7{#/blank#}(close) connected with the daily life of people in ancient China. Su Dongpo, a literary giant of the Song Dynasty, said that people could not live {#blank#}8{#/blank#}bamboo, and people of the time used bamboo {#blank#}9{#/blank#}(make) paper, hats, shoes and so on. At that time, as today, bamboo shoots were eaten as a popular dish because of {#blank#}10{#/blank#}(they) crispness and fresh, sweet taste. Bamboo shoots also contain vitamins, sugar, fat, and protein.