Caffeine not only gives us a daily jump start, but new research suggests it also can strengthen long-term memory.
According to the US Food and Drug Administration, nearly 90 percent of people worldwide consume about 200 milligrams of caffeine each day. That' s equivalent to about one strong cup of coffee a day. Writing in " Nature Neuroscience" , Johns Hopkins University researchers say their findings show that caffeine strengthens certain memories for up to 24 hours after being taken in.
" We've always known that caffeine has cognitive-enhancing effects (促智效果) , but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans, " said senior author of the paper Michael Yassa. " We re- port for the first time a specific effect of caffeine on reducing forgetting over 24 hours. " Conducting a double-blind trial, the researchers worked with a test group of people who didn't regularly consume caffeinated products. Five minutes after studying a series of images, the test subjects were given either a placebo(无效对照剂) or a 200-milligram caffeine tablet.
To check the caffeine levels of their test subjects, the research team took saliva samples (唾液样品) from them before they took their tablets and again one, three and 24 hours afterwards.
Both groups of test participants ( those who took the placebo and those who took the caffeine tablet) were tested the following day to see if they could recognize the images they' d seen the previous day.
The test included showing the test subjects another series of images that included some new images , those that were shown the previous day, as well as other images that were similar, but not the same as those they had viewed earlier.
The researchers found that more members of the group who were given the caffeine tablets were able to correctly identify some of the new images as " similar" to previously viewed images rather than incorrectly identifying them as the same.
"We also know that caffeine is associated with health and longevity(长寿) and may have some protective effects from cognitive decline like Alzheimer' s disease (阿尔茨海默症). " said Yassa.
1.The purpose of the new research is ____________.
A．to examine caffeine ' s memory-strengthening effects in detail
B．to write the paper " Nature Neuroscience"
C．to prove caffeine has cognitive-enhancing effects
D．to survey how much caffeine people consume a day
2. During the research , the researchers did the following things EXCEPT ________.
A．giving the test subjects placebos or caffeine tablets
B．checking the caffeine levels of the test subjects
C．showing the test subjects series of images
D．encouraging the test subjects to drink more coffee
3. How did the test subjects show the caffeine ' s memory-strengthening effects?
A．By taking the caffeine tablets instead of placebos.
B．By recognizing images they ' d seen the previous day.
C．By identifying the new images as the same.
D．By telling the differences between new images.
4.What will the next part of the text possibly talk about?
A．Ways to achieve health and longevity.
B．The harmful effects of cognitive decline.
C．The treatment for Alzheimer' s disease.
D．The effects caffeine has on health.
Here is an astonishing and significant fact: Mental work alone can’t make us tired. It sounds absurd. But a years ago, scientists tried to find out how long the human brain could labor without reaching a stage of fatigue (疲劳). To the amazement of these scientists, they discovered that blood passing through the brain, when it is active, shows no fatigue at all! If we took a drop of blood from a day laborer, we would find it full of fatigue toxins(毒素) and fatigue products. But if we took blood from the brain of an Albert Einstein, it would show no fatigue toxins at the end of the day.
So far as the brain is concerned, it can work as well and swiftly at the end of eight or even twelve hours of effort as at the beginning. The brain is totally tireless. So what makes us tired?
Some scientists declare that most of our fatigue comes from our mental and emotional(情绪的) attitudes. One of England’s most outstanding scientists, J.A. Hadfield, says, “The greater part of the fatigue from which we suffer is of mental origin. In fact, fatigue of purely physical origin is rare.” Dr. Brill, a famous American scientist, goes even further. He declares, “One hundred percent of the fatigue of sitting worker in good health is due to emotional problems.”
What kinds of emotions make sitting workers tired Joy Satisfaction No! A feeling of being bored, anger, anxiety, tenseness, worry, a feeling of not being appreciated---those are the emotions that tire sitting workers. Hard work by itself seldom causes fatigue. We get tired because our emotions produce nervousness in the body.
1.What surprised the scientists a few years ago?
A. Fatigue toxins could hardly be found in a laborer’s blood.
B. The brain could work for many hours without fatigue.
C. Albert Einstein didn’t feel worn after a day’s work.
D. A mental worker’s blood was filled with fatigue toxins.
2. According to the author, which of the following can make sitting workers tired?
A. Challenging mental work. B. Endless tasks.
C. Physical labor. D. Unpleasant emotions.
3. Which of the following is properly used to describe the author’s attitude to the scientists’ idea?
A. He hesitates to accept them. B. He doubts them.
C. He argues against them. D. He agrees with them.
4. It is implied in the passage that in order to stay energetic, sitting workers need to ___________.
A. enjoy their work B. have some good food.
C. exercise regularly D. discover fatigue toxins
I wish there would be a way to describe China in simple terms but that’s impossible. For the most part, Chinese people are friendly, easy-going and optimistic. They are curious and unusually patient and they are also the hardest-working people I have ever met.
In China, family is everything. In my English classes when the students were asked what they would do if they only had a few hours to live, most students told me how they would spend their last few hours with their families and parents. Many times the subjects in the classes center on families and friends. I teach many students a year, talking to them freely.
The cost of living here is very low compared with that of the US. The city of Xiang Fan I live in isn’t large and I live better. Non-imported(非出口的) foods are very cheap, so are clothing and articles of everyday use. The cost of public transportation is very low, too. Chinese value education. However, it is reported that many children can’t afford the expenses of schooling and are forced to leave school in some poor areas in China. But they organized Project Hope many years ago. It creates conditions for the poor children to go back to school. In my opinion, Project Hope is of great importance to the development of the rural education.
When we read news of China in the west, rarely, if ever, will we see anything mentioned of the positive changes China has gone through. While it is true that economic miracles have not reached many areas of China, but we also have the same problems.
When I am asked which country I consider better. China or the US, my answer has always been the same, “We are not worse or better than each other, we are only different.”
1. How does the author find Chinese people ?
A．He thinks most Chinese people hardly work.
B．He praises most Chinese people a lot.
C．He thinks most Chinese people are proud.
D．He dislikes most Chinese people.
2.What are not cheap in China in the author’s opinion?
A．Imported foods
B．Local foods
C．Public transportation tickets.
D．Clothes and shoes made in China.
3.We can infer from the passage that the author thinks________.
A．the westerners have got to know China well
B．China’s economic miracles have appeared everywhere
C．the education in rural areas is never cared about in China
D．the progress of China is seldom reported in the US
4. In the author’ eyes,________.
A．China is better than the US
B．China is different from the US
C．Americans are richer than Chinese
D．China bears great similarities to the US
书面表达
假如你是李华，是校刊记者。请你为校刊写一篇英语短文，介绍最近在我国很多城市发生的雾霾（haze）天气。请参考以下要点：
1. 危害；
2. 原因；
3. 如何自我防护。
注意：
1. 词数100左右；
2. 开头已给出，不计入总词数。
Recently haze pollution has happened in many cities of China.
________________________________________________________________________________________
________________________________________________________________________________________
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短文改错
假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号(
)，并在其下面写出该加的词。
删除：把多余的词用斜线(＼)划掉。
修改：在错的词下画一横线，并在该词下面写出修改后的词。
注意：1．每处错误及其修改均仅限一词；
2．只允许修改10处，多者(从第11处起)不计分。
There are many similarity between doctors and teachers. First, both doctors and teachers are considering professionals by their communities. The classification of professionals is the high socioeconomic rank where an individual can achieve in this society. Second, both doctors and teachers help others: doctors heal to the bodies of sick people and return them to healthy. And teachers shape the minds of young people and turn them into responsible, educating adults. Last, both doctors and teachers are essential members of a community. It is difficult to imagine a city or town that has not need of neither a doctor or a teacher. Such place would truly be primitive.
阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。
Some of us feel puzzled about the 1. (participate) of a debate. Here is some information which will help you get a general idea of it.
Participating in a debate is a useful practice of those who aim to become public speakers. In a formal debate a statement called a “motion” is 2. (propose). It is defended by the proposers and challenged by their opponents. To become a 3. (lead) debater it is necessary to acquire several techniques and skills. 4. experienced debater seeks to persuade others by presenting relevant arguments 5. (intention), not by the violence of his language. He shows respect for standpoints which 6. (different) from his own and does not allow personal hostility to enter into 7. should be a conflict of ideas. He anticipates the points put forward by his opponent and deals with them methodically. He attempts to present a 8. (consist) case, 9. rather, a piece of reasoning free from self-contradiction. He realizes that the 10. (accept) conclusions must be supported by adequate evidence. He knows how to sum up the various points that arise in the course of the debate.
