Have you ever fancied sailing around the world or buying a holiday home in the Caribbean? Well, before you get too excited, it may help to find out if you have what it takes to become a billionaire.   

    We've all heard stories of school drop-outs who have made their fortune. Do they tend to be university graduates or self-made successful people? Are they married or single?

    Thanks to a recent analysis of people in Forbes（福布斯）Top 100 Billionaires List, we can now find out what they have in common. We know what percentage wear glasses and even how many are bald!

    If you are deciding whether or not to go to university, it may help you to know that 76% of the richest people in the world have a degree. According to this study, of those 76%, 47% have a bachelor's degree, 23% have a master's and 6% have a doctorate. Don't lose hope if you aren't very academic, though. It's worth noting that many of those on the list did not pass all their exams with flying colors. Microsoft founder Bill Gates dropped out of Harvard University after two years of study. And Chinese business magnate Jack Ma, failed his university entrance exams three times before going on to complete his degree and make his millions.

    Another interesting trend is that the world's richest people are much more likely to be married - only 12% of billionaires are unmarried. Finally, the percentage of billionaires who are bald is quite high – so don't worry if you're losing your hair.

    However wealthy we may be, we can never find enough hours in the day to do everything we want. Economics deals with this problem through the concept of opportunity cost, which simply refers to whether someone's time or money could be better spent on something else.

    Every hour of our time has a value. For every hour we work at one job we could quite easily be doing another, or be sleeping or watching a film. Each of these options has a different opportunity cost—namely, what they cost us in missed opportunities.

    Say you intend to watch a football match but the tickets are expensive and it will take you a couple of hours to get to and from the stadium. Why not, you might reason, watch the game from home and use the leftover money and time to have dinner with friends? This—the alternative use of your cash and time—is the opportunity cost.

    For economists, every decision is made by knowledge of what one must forgo—in terms of money and enjoyment—in order to take it up. By knowing precisely what you are receiving and what you are missing out on, you ought to be able to make better-informed, more reasonable decisions. Consider that most famous economic rule of all: there's no such thing as a free lunch. Even if someone offers to take you out to lunch for free, the time you will spend in the restaurant still costs you something in terms of forgone opportunities.

    Some people find the idea of opportunity cost extremely discouraging: imagine spending your entire life calculating whether your time would be better spent elsewhere doing something more profitable or enjoyable. Yet, in a sense it's human nature to do precisely that—we assess the advantages and disadvantages of decisions all the time.

    In the business world, a popular phrase is “value for money.” People want their cash to go as far as possible. However, another is fast obtaining an advantage: “value for time.” The biggest restriction on our resources is the number of hours we can devote to something, so we look to maximize the return we get on our investment of time. By reading this passage you are giving over a bit of your time which could be spent doing other activities, such as sleeping and eating. In return, however, this passage will help you to think like an economist, closely considering the opportunity cost of each of your decisions.

    Australian scientists are trying to give kangaroo-style stomachs to cattle and sheep in order to cut the greenhouse gases they send out, which is thought to be responsible for global warming.

    Thanks to special bacteria in their stomachs, kangaroo flatulence (肠胃气胀) contains no methane and scientists want to transfer that bacteria to cattle and sheep who produce large quantities of the harmful gas.

    While the usual image of greenhouse gas pollution is a billowing smokestack, pushing out carbon dioxide, farm animals' passing wind contribute a surprisingly high percentage of total emissions in some countries.

    “Fourteen percent of emissions from all sources in Australia are from enteric methane from cattle and sheep,” said Athol Klieve, a senior research scientist with the greensland state government. “And if you look at another country such as New Zealand, which has got a much higher agricultural base, they are actually up around 50 percent,” he said.

    Researchers say the bacteria also make the digestive process much more efficient and could potentially save millions of dollars in feed costs for farmers. But it will take researchers at least three years to isolate the bacteria before they can even start to develop a way of transferring it to cattle and sheep.

    Another group of scientists, meanwhile, have suggested Australians should farm fewer cattle and sheep and just eat more kangaroos. And about 20 percent of health-conscious Australians are believed to eat the national symbol already.

    It's low in fat, it's got high protein levels and it is very clean in the sense that basically it is free-range(放养的) animal,” said Peter Ampt of the University of New South Wales' institute of environmental studies.

    The aye-aye, in the same family as people, monkeys and apes, is about 40 cm long, with a bushy tale about the same length as the body. The dark brown fur is long and woolly, giving the animal a rather shaggy(蓬松的) appearance. They are found only on Madagascar, an island off the coast of Africa. It lives in the tropical forests in the east and north of Madagascar.

    The aye-aye is mostly arboreal(栖息在树上的), but is sometimes seen walking on the ground. It's active during the night, looking around in the trees for food. The aye-aye is actually the largest primate(灵长类动物) active during the night. Large eyes help the aye-aye find its way about at night. During the day, the aye-aye sleeps in a nest in a tree. Aye-ayes spend almost the whole night travelling about and feeding.

    Aye-ayes live alone. Sometimes pairs are seen, but basically little is about their lives. They don't Icap and cling to trees like primates. They move about on all four legs.They occasionally make brief cries but are silent. Worms inside dead wood form the largest part Of the aye-aye diet. The aye-aye also feeds on fruit, eggs, and bamboo shoots.

    The front feet of the aye-aye are unique. All the toes are long and thin, but the third is exceptionally long. The aye-aye taps on the tree trunk and listens for movement as searches places "'here worms might-be located. It bites at the tree to make homes. then it uses its third finger to reach inside and hook out worms, The front teeth of the aye-aye grow continuously and are worn down by its eating at bark in its search for worms.

    Aye-ayes are close to be gone or totally gone. Because of deforestation (伐木), or forest destruction, the animals have therefore been forced to eat villagers' crops, and many aye-ayes been  have been killed while doing In addition. Some people on Madagascar believe that seeing an aye-aye is a sign that someone close to them will die, so they kill the animals on sight.

    Galaxy saw a man and a woman who communicated with the sign language at the train station when she was on the way home one evening. She noticed that the woman asked the man for the direction. He told her that he did not know. Galaxy decided to help them. She had learned the sign language when she served as a volunteer in the deaf and mute (聋哑) school. Then she showed the woman the direction and left her email address to them in case they needed her help later.

    She received an email from that man the next day. Kazrim was his name. Galaxy replied to his mail sincerely. They both started chatting online soon after and began seeing each other. Although they only communicated with the sign language, it never bothered her.

    Galaxy was fond of him gradually. Obviously, Kazrim was the same too. He presented Galaxy with a bunch of sunflowers and asked her sincerely, "Are you willing to be my girlfriend?" Galaxy was pleasantly surprised. She requested him to give her some time to persuade her parents.

    As she had expected, her parents were very angry after they had learned of their love story. Galaxy explained, "Kazrim is an excellent and a very optimistic person. He has a very positive attitude towards life and work. He cares for others always. He is 100% better than the normal. Moreover, the mute is still a human. He should have a perfect and wonderful love."

    Her parents asked to see him, then. The very worried Galaxy took Kazrim home a few days later. When they were on the train, Kazrim told her, "I'm going to tell your parents I'll be looking after you well with all my life!" Galaxy was deeply moved.

As soon as they had entered the house, Galaxy introduced him to her parents. She said, "This is Kazrim." Just right after her speech, an unbelievable thing happened. Kazrim threw the gift away and held her in his arms tightly.

    He said, "YOU CAN TALK?" It was the same question that Galaxy wanted to ask, too.

    The four people were shocked all of a sudden. As a matter of fact, Kazrim always believed that Galaxy was a mute and he still fell in love with her deeply.

    Laughter is part of the universal human vocabulary. All members of the human species understand it. Unlike English or French or Swahili, we don't have to learn to speak it. We re born with the capacity to laugh.

    Very little is known about the specific brain mechanisms responsible for laughter. Contrary to folk wisdom, most laughter is not about humor; it is about relationships. To find out when and why people laugh, I went with several assistants to local malls and recorded what happened just before people laughed. Over a 10-year period, we studied over 2, 000 cases of naturally occurring laughter.

    We found that most laughter does not necessarily follow jokes. People may laugh after a variety of statements, such as, "Here comes Mary," "How did you do on the test?" or "Do you have a rubber band?" These certainly aren't jokes.

    We believe laughter evolved from the panting (喘气的) behavior of our ancient ancestors. Today, if we tickle (使发痒) chimps, they don't laugh. But, instead, they produce a panting sound. That's the sound of ape laughter, and it's the root of human laughter.

    Apes laugh in the kinds of situations that lead to human laughter, like games that involve chasing. Other animals produce sounds during play, but they are so different from laughter. Rats, for example, produce high sounds during play and when tickled, but these are very different in sound from human laughter.

    Laughter is often positive, but it can be negative too. There's a difference between "laughing with" and "laughing at". People who laugh at others may be trying to drive them out of the group.

    No one has actually counted how much people of different ages laugh, but young children probably laugh the most. At ages 5 and 6 we probably laugh more than at any other times. Adults laugh less than children, probably because they play less.

    Work now underway will tell us more about the brain mechanisms behind laughter, how it has evolved, and why we're so susceptible to tickling.