The baby monkey is much more developed at birth than the human baby. Almost from the moment it is born, the baby monkey can move around and hold tightly to its mother. During the first few days of its life the baby will approach and hold onto almost any large, warm, and soft object in its environment, particularly if that object also gives it milk. After a week or so, however, the baby monkey begins to avoid newcomers and focuses its attentions on “mother” — the real mother or the mother-substitute(母亲替代物）.

During the first two weeks of its warmth is perhaps the most important psychological（心理的） thing that a monkey mother has to give to its baby. The Harlows, a couple who are both psychologists, discovered this fact by offering baby monkeys a choice of two types of mother-substitutes — one covered with cloth and one made of bare wire. If the two artificial mothers were both the same temperature, the little monkeys always preferred the cloth mother. However, if the wire model was heated, while the cloth model was cool, for the first two weeks after birth the baby monkeys picked the warm wire mother-substitutes as their favorites. Thereafter they switched and spent most of their time on the more comfortable cloth mother

    Why is cloth preferable to bare wire? Something that the Harlows called contact（接触的） comfort seems to be the answer, and a most powerful influence it is. Baby monkeys spend much of their time rubbing against their mothers' skins, putting themselves in as close contact with the parent as they can. Whenever the young animal is frightened, disturbed, or annoyed, it typically rushes to its mother and rubs itself against her body. Wire doesn't“rub”as well as does soft wire cloth. Prolonged（长时间的）“contact comfort” with a cloth mother appears to give the babies confidence and is much more rewarding to them than is either warmth or milk.

    According to the Harlows, the basic quality of a baby's love for its mother is trust. If the baby is put into an unfamiliar playroom without its mother, the baby ignores the toys no matter how interesting they might be. It screams in terror and curls up into a fury little ball. If its cloth mother is now introduced into the playroom, the bay rushes to it and holds onto it for dear life. After a few minutes of contact comfort, it obviously begins to feel more secure. It then climbs down from the mother-substitute and begins to explore the toys, but often rushes back for a deep embrace（拥抱）as if to make sure that its mother is still there and that all is well. Bit by bit its fears of the new environment are gone and it spends more and more time playing with the toys and less and less time holding on to its “mother.”

    The insects are important to farmers. When a honeybee lands on a flower in plant, pollen (花粉) sticks to its legs. When the bee lands on another flower, some of the pollen falls off and fertilizes the second plant.

    The act of spreading pollen is responsible for many fruits, vegetables, nuts and other crops. Yet about 30 percent of honeybees in the United States and other areas have died in recent years.

    Mike Leggett is a researcher at the University of Maryland. He wants to learn why so many bees are dying. “The number of colonies (蜂群) that die every winter has been one in three. So on average 30 percent of the colonies have died every winter over the last six winters. And that's a huge number.” His research team examined the pollen that honeybees carried to their homes. They found that the pollen contained high levels of 35 different pesticides (杀虫剂), which are chemicals used to protect plants. “Pesticides are used, and have been used, pretty widely, for centuries, to protect plants from diseases,” says Mr Leggett.

    Keith Oh linger, a farmer and beekeeper in Maryland, has watched many of his bees die every winter. Mr Ohlinger thinks widespread bee death is caused by several things happening at once. But he does not feel sure that pesticides are a part of the problem, “I felt it was the result of a lot of little things. I didn't feel that there was probably one smoking gun. But there's a division (分歧) there, some people feel that it is just one thing.”

    Honeybees are important to agriculture. This makes the search for an answer to their death very important for Mr Leggett's team. As he knows, one in every three bites of food we eat is somehow pollinated by honeybees.

    Reading may be fundamental, but how the brain gives meaning to letters on a page has been a mystery. Two new studies fill in some details on how the brains of efficient readers handle words. One of the studies, published in the April 30 Neuron, suggests that a visual-processing area of the brain recognizes common words as whole units. Another study, published online April 27 in PLOSONE, makes it known that the brain operates two fast parallel systems for reading, linking visual recognition of words to speech.

    Maximilian Riesenhuber, a neuroscientist at Georgetown University in Washington, D. C. , wanted to know whether the brain reads words letter by letter or recognizes words as whole objects. He and his colleagues showed sets of real words or nonsense(无意义的词语)words to volunteers undergoing FMRI scans. The words differed in only one letter, such as “farm” and “form” or “soat” and “poat”, or were completely different, such as “farm” and “coat”or “poat” and “hime”.The researchers were particularly interested in what happens in the visual word form area, or VWFA, an area on the left side of the brain just behind the ear that is involved in recognizing words.

    Riesenhuber and his colleagues found that neurons(神经元)in the VWFA respond strongly to changes in real words. Changing “farm” to “form”, for example, produced as great a change in activity as changing “farm” to“coat”, the team reports in Neuron. The area responded slowly to single-letter changes in made-up words.

    The data suggests that readers grasp real words as whole objects, rather than focusing on letters or letter combinations. And as a reader's exposure to a word increases, the brain comes to recognize the shape of the word. “Meaning is passed on after recognition in the brain”, Riesenhuber says.

    The researchers don't yet know how longer and less familiar words are recognized, or if the brain can be trained to recognize nonsense words as a unit.

    Outside, it's a cold winter's day. Inside a large shopping center, people are hanging around. But then, without warning, a pop song starts to play loudly. A teenager boy walks lazily to the center of the open space, and dances crazily to the music. He's joined by two of his friends, then some of the old people. Within the space of a few seconds, more than sixty people are dancing to the music - all in time and all in step. At first, onlookers are baffled, then they start smiling and clapping. They now know what they're seeing: a flash mob （快闪）.

    According to Wikipedia, the term "flash mob" was created by Bill Wasik, an editor at Harper's Magazine, in 2003. Within a year, the phrase had entered the Concise Oxford English Dictionary. Since then, hundreds - possibly thousands - of flash mobs have been carried out around the world, in almost every kind of public space imaginable!

    Each flash mob has its own style, but most flash mobs follow a similar formula （方案）. Often, the organizers search for willing participants using social media. Instructions and dance moves are given through email or video download. There are usually several rehearsals （排练） before the big day.

    While it's happening, a few lucky passers-by watch it live. Most people who watch it, however, will see it later online. Some of the most popular flash mobs on YouTube have been watched more than 10million times. A famous example is MP3Experiment Eight, a flash mob that took place in New York City in July 2011 with over 3,500 participants. This event differed from normal flash mobs in that much of it was completely silent - and there were no rehearsals.

    Flash mobs provide the participants, onlookers and online viewers with a lot of enjoyment and pleasure. For this reason alone, they're a modern, popular art form that should be celebrated.

    AI(人工智能)makes our lives easier and better. Let's see the amazing AI.

    A headache is the feeling you get when your head hurts. Headaches can differ from very mild to incredibly powerful. They can last anywhere from 10 minutes to hours. Very bad headaches are called migraines. People who suffer from migraine headaches often need to take the day off from school or work and lie in bed all day.

    Why do people get headaches? There are many possible causes. People who drink too much caffeine (in coffee or soft drinks, for example) or alcohol can end up with headaches. This is because these kinds of drinks take water away from the body. If the brain doesn't have enough water, it gets smaller and pulls away from the head. This can be extremely painful. The best way to get rid of this kind of headache is just to drink lots of water.

    Tension headaches happen when the body's muscles are too tight. When people feel stress, it is common for the muscles near the head to become tense. Tension headaches might also be caused by not getting enough sleep. Some people suffer from tension headaches for only short times but for other people, these kinds of headaches are a chronic problem that happens again and again. A massage (按摩) might help to stop a tension headache. If that doesn't help, you might need to see a doctor.

    Headaches can also be caused by much bigger health problems. For example, a head or neck injury can cause them. Headaches can also be a warming sign of a heart attack.