Food is one of the necessities in our daily life. It serves as a form of communication in two fundamental ways. Sharing bread or other foods is a common human tradition that can promote unity and trust. Food can also have a specific meaning, and play a significant role in a family or culture's celebrations or traditions. The foods we eat—and when and how we eat them—are often unique to a particular culture or may even differ between countrysides and cities within one country.

    Sharing bread, whether during a special occasion or at the family dinner table, is a common symbol of togetherness. Many cultures also celebrate birthdays and marriages with cakes that are cut and shared among the guests. Early forms of cake were simply a kind of bread, so this tradition hits its roots in the custom of sharing bread.

    Food also plays an important role in many New Year celebrations. In the southern United States, pieces of corn bread represent blocks of gold for prosperity (兴旺) in the New Year. In Greece, people share a special cake called vasilopita. A coin is put into the cake, which signifies (预示) success in the New Year for the person who receives it.

    Many cultures have ceremonies to celebrate the birth of a child, and food can play a significant role. In China, when a baby is one month old, families name and welcome their child in a celebration that includes giving red-colored eggs to guests. In many cultures, round foods such as grapes, bread, and moon cakes are eaten at welcome celebrations to represent family unity.

    Nutrition is necessary for life, so it is not surprising that food is such an important part of different cultures around the world.

    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.

    During the period from 1660 through 1800, Great Britain became the world's leader. Language itself became submitted to rules during this period. This need to fix the English language is best illustrated (描述) in the making of The Dictionary of the English Language by Samuel Johnson. Guides to the English language had been in existence before Johnson began his project in 1746. These, however, were often little more than lists of hard words. When definitions of common words were supplied, they were often unhelpful. For example, a "horse" was defined in an early dictionary as "a beast well known".

    Johnson changed all that, but the task was not an easy one. Renting a house at 17 Gough Square, Johnson began working in the worst of conditions. Supported only by his publisher, Johnson worked on the Dictionary with five assistants. Compared to the French Academy's dictionary, which took forty workers fifty-five years to complete (1639-1694), Johnson's dictionary was completed by very few people very quickly.

Balanced on a chair with only three legs, Johnson sat against a wall in a room filled with books. Johnson would read widely from these books, mark passages illustrating the use of a particular word, and give the books to his assistants so that they could copy the passages on slips of paper. These slips were then stuck to eighty large notebooks under the key words that Johnson had selected. Fixing the word by this method, Johnson could record a word，s usage and its definition.

    How many passages were used? According to Johnson's modern biographer Walter Jackson Bate, the original total number could have been over 240,000. How many words were defined by the lexicographer? Over 40,000 words appeared in two large books in April of 1755. Did Johnson fully understand the huge task he was undertaking when he began? As he told his contemporary biographer James Boswell, "I knew very well what I was undertaking and very well how to do it — and have done it very well."

    On December 26, 2004, hundreds of tourists relaxed on Sri Lanka's Yala National Park's beaches. But at mid-morning the park's elephants began crying wildly and running away from the ocean and up a nearby hill. The puzzled keepers could tell the animals were worried about something but what?

    What the keepers did not know was that a 30-foot wall of water was headed straight toward them. This tsunami(海啸) had been caused by an earthquake more than 1, 000 miles away in the Indian Ocean. When the huge wave hit the coast, it caused severe damage. Many people died. The elephants, however, were not swept away by the water. They stood safely on the hill.

    Scientists have long suspected that animals sense natural disasters before humans do. People have told stories of dogs refusing to go outside and sharks swimming to deeper waters before a hurricane. After the 2004 tsunami, people said they saw tigers, monkeys, and water buffalo escaping to higher ground before the waters rushed in. Even in the hardest-hit areas of southern Asia, there were few animal deaths.

    It's unlikely that an animal's so-called sixth sense comes from some magical power to see into the future. Experts believe that animals may be more sensitive than humans to changes in temperature and other environmental conditions that take place before a natural disaster. The elephants in Sri Lanka, for example, may have picked up vibrations from within the Earth, a sign that earthquake was coming. Because vibrations in the ground travel much faster than an ocean wave, the elephants may have felt the earthquake that caused the tsunami well before the tsunami itself came to the coast.

    A few scientists are calling for a system to track reports of strange behavior in people's pets, hoping that these reports can serve as a warning system that a natural disaster is about to happen. But Marina Haynes, an animal behavior scientist at the Philadelphia Zoo, says, "It would be an unreliable way to predict disasters. It can be difficult to know what an animal is doing. Is the animal nervous because an earthquake is about to happen or is it frightened because there is an enemy nearby?"

    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 claw s ( 爪) on its wings when young. They build their homes about 4.6m above the river, an important feature 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 (远古的) 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.

When we're on the treadmill（跑步机）, we're more likely to bethinking about whether we're going to make it another mile than'what's in our workout clothing. But our favorite sports ch ab are likely to be made from synthetic （合成的） fabrics, all of which are essenally plastic often created with harmful chemical additives. Now, a study conducted by the University of Birmingham shows the chemical additives from our workout clathing are available

to be absorbed through our skin.

Previously, researchers have tended to focus on our exposure to plastic through diet,but the new study raises awareness that humans can be expesed to plastic chemicals through our skin, too. And because harmful chemicals accumulate lowly and stick around in our bodies, repeared and multi-source exposure can result in having high

concentrations of chemicals inside us, potentially contributing to health effects.

The Birmingham study focused on a class of compounds（化合物）called brominated flame retardants（BFRs）, which are used to prevent. burning in a wide range of consumer products including fabries, and are linked to adverse

health effects such as hormonal disorders and mental problems.

It's known that sweat contains oil. Researchers found the oil has a chemical nature that encourages the chemicals in plastic to dissolve and spread."In short, oil y substances in our sweat help the bad chemicals to come out of the microplastic fibers and become available for human absorption,"says Dr. Abdallah of the Urnversity of Birmingham. An easy way to avoid exposure ta these chemicals is to wear clothing made of sustainably produced textiles, which dont contain the bad chemicals associated with plastic materials. Check fabric labels for items that are mostly organic cotton, he mp or merino wool. Visit brand websites to see if they make an effort to list their suppliers, and where their products come from, including their dye houses and mills. Abdallah says he minimizes synthetic fabrics

in his home, meanwhile wearing natural fibers like cotton. "Why be exposed to these chemicals even at low levels?" he says. "Why not avoid the risks?"