A study published in Child Development,the top－ranked educational psychology journal,provides some of the strongest evidence yet that gesturing may have a unique effect on learning.Teachers in the United States tend to use gestures less than teachers in other countries.

     "Gesturing can be a very beneficial tool that is completely free and easily employed in classrooms," said Kimberly Fenn,study co－author and assistant professor of psychology at Michigan State University."And I think it can have long－lasting effects."

    Fenn and Ryan Duffy of MSU and Susan Cook of the University of Iowa conducted an experiment with 184 second－,third－ and fourth－graders in Michigan elementary classrooms.

    Half of the students were shown videos of an instructor teaching math problems using only speech.The others were shown videos of the instructor teaching the same problems using both speech and gestures.In the speech－only videos,the instructor simply explains the problem.In the other videos,the instructor uses two hand gestures while speaking,using different hands to refer to the two sides of the equation.Students who learned from the gesture videos performed better on a test given immediately afterward than those who learned from the speech－only video.

    Another test was given 24 hours later,and the gesture students actually showed improvement in their performance while the speech－only students did not.

    While previous research has shown the benefits of gestures in a one－on－one tutoring－style environment,the new study is the first to test the role of gestures in equivalence learning in a regular classroom.

    The study also is the first to show that gestures can help students transfer learning to new contexts—such as transferring the knowledge learned in an addition－based equation to a multiplication－based equation.

    Fenn noted that U.S.students lag behind those in many other Western countries in math and have a particularly hard time mastering equivalence problems in early grades."So if we can help them grasp this foundational knowledge earlier," she said,"it will help them as they learn algebra and higher levels of mathematics."

    Ever feel like you've been hit on the head after a bad night's sleep? According to scientists, the thought isn't as unbelievable as it seems.

    A study found going without sleep for just one night causes changes in the brain similar to those that occur after a blow to the head. The researchers said the healthy young men examined in the study showed a sudden increase in the same chemicals which indicate brain damage. Professor Christian Benedict, of Uppsala University, Sweden, explained that the chemicals NSE and S-100B are biomarkers for brain damage, such as concussion(脑震荡). He said, "What we found was their levels in the blood rose in the group that went without sleep for a night. This was not to the extent that would happen after a head injury, for instance, but it was still significant. During sleep, the brain cleans poisonous substances off itself."

    Benedict also said previous studies which linked a lack of sleep with increased risk of Alzheimer's, Parkinson's and multiple sclerosis could applaud his study. The rise of the chemicals in the blood after sleep loss may suggest not getting enough sleep contributes to a loss of brain tissue, he explained. Benedict, whose study is published in the journal Sleep, added, "In conclusion, the findings of our experiment indicate a good night's sleep may be critical to maintaining brain health."

    A third of the UK population suffer from sleep-related problems, while the average person now sleeps for only seven hours a night, compared with almost nine a few decades ago. Many scientists believe irregular sleeping patterns lead to illnesses ranging from aches and pains to heart disease, while less than eight hours' sleep a night can lower the IQ the next day.

    {#blank#}1{#/blank#} When a starving man gets a meal, he begins to think about an overcoat; when a manager gets a new sports car, visions of country clubs dance into view.

    The many wants of mankind might be regarded as making up several levels. {#blank#}2{#/blank#}.

    The first and most basic level of wants is food. Once this want is satisfied, a second level of wants appears: clothing and some sort of shelter. By the end of World War II these wants were satisfied for a great majority of Americans. {#blank#}3{#/blank#} It included such items as cars and new houses.

    By 1957 or 1958 this third level of wants was fairly well satisfied. Then, in the late 1950s a fourth level of wants appeared: the “life-enriching” level. While the other levels mean physical satisfaction－the feeding, comfort, safety, and transportation of the human body－this level stresses mental needs for recognition, achievement and happiness. It includes a variety of goods and services, many of which could be called “luxury” items(奢侈品). Among them are vacation trips, the best medical care, and entertainment. {#blank#}4{#/blank#}

    On this level, a greater percentage of consumer spending goes to services, while on the first three levels more is spent on goods. Will consumers raise their sights to a fifth level of wants as their income increases, or will they continue to demand luxuries and personal services on the fourth level?

    A fifth level probably would be wants that can be achieved best by community action. Consumers may be spending more on taxes to pay for government action against disease, ignorance, crime and prejudice. {#blank#}5{#/blank#} In this way, we can enjoy more fully the good things on the first four levels.

 A．Then a third level appeared.

 B．Human wants seem endless.

 C．When there is money enough to satisfy one level of wants, another level appears.

 D．There are several levels of wants in one's life.

 E．At this stage, we now may seek to ensure the health, safety, and leisure.

 F．Also included here are fancy foods and the latest styles in clothing.

 G．Different people have different wants on each level 

    Most dog owners are convinced that their four-legged friends know exactly what they mean when they use certain words like sit, stay or treat. However, researchers have always wondered whether dogs really understand human speech or if they rely on other information to get the meaning. For example, does the word “fetch” form a picture of a stick or ball in the dog's mind, or does the dog bring back the object based on the owner's voice or gesture? A new study by scientists at Atlanta's Emory University seems to indicate that “man's best friend” does indeed know what the owner is saying.

    The researchers began by asking the owners of twelve dogs of various kinds to train their pets to identify two toys of different materials, such as a toy animal and a ball. Once the dogs had mastered the task, they took turns inside a special scanner. The owners then tested their dog's language skill by first calling out the names of the toys they had been trained to recognize and then saying meaningless words such as “bobbu” and “bodmick” while holding up random objects the dogs hadn't seen before.

    The scans suggested that the parts of the dogs' brains responsible for processing of sounds showed different brain patterns when they heard words they were familiar with, compared with the ones they had never heard before. While that was not enough to prove that the dogs were picturing their toys when they heard the word, it did indicate some sort of recognition. The researchers believe this is an important step forward in understanding how dogs process language.

    Even more interesting was that the dog's brains showed a higher level of neural(神经)activity at the sound of unknown words. This is the exact opposite of what happens in human brains, which get more active at the sound of familiar words. The researchers say the dogs may become cheerful at the sound of new words to try to understand them in the hope of delighting their masters. “Dogs want to please their owners, and perhaps also receive praise or food,” says Empty neuroscientist Gregory Burns, senior author of the study.

    However, though your pet may understand human speech, the scientists recommend using visual signals and smell for training. “When people want to teach their dog a trick, they often use spoken command because that's what humans prefer, ”Prichard says.“ From the dog's view, however, a visual command might be more effective, helping the dog learn the trick faster.”

    Have you ever considered all the English expressions that include words about clothes? Let's have a look.

    People wear pants to cover the lower part of their bodies. We sometimes say that people who are nervous have ants (蚂蚁) in their pants. Sometimes, people may get caught with their pants down. They are found doing something they should not be doing. And, in every family, one person takes control. Sometimes a wife tells her husband what to do. Then we say she wears the pants in the family.

    Pants usually have pockets to hold things. Money that is likely to be spent quickly can burn a hole in your pocket. Sometimes you need a belt to hold up your pants. If you have less money than usual, you may have to tighten your belt.

    I always praise people who can save their money and not spend too much. I really take my hat off to them. Yet, when it comes to my own money, I spend it at the drop of a hat, which means I instantly spend it.

    Boots are a heavy or strong kind of shoes. People who are too big for their boots think they are more important than they really are. I dislike such people. My father is an important person. He runs a big company. He wears a suit and tie, and a shirt with sleeves (衣袖) that cover his arms. Some people who do not know him well think he is too serious and never shows his feelings openly. But I know that my father wears his heart on his sleeve.