READING COMPREHENSION

　　The new automobile fuel economy standards formally adopted by the Obama administration on Thursday will produce a series of benefits：reduced dependence on foreign oil, fewer greenhouse gas emissions(排放), and consumer savings at the pump．

　　This was truly a moment to celebrate．But it was tempered by the fact that some in Congress are trying to cancel the laws that made the new standards possible．

　　The standards will require automakers to build passenger cars, sport-utility vehicles and minivans that average 35.5 miles per gallon by 2016－a 30 percent increase over today’s cars, and the biggest single jump in fuel economy since the original standards were adopted in the 1970s．Cars will cost more, but the government estimates that consumers will save an average of ＄3,000 in fuel over the life of a new vehicle．

　　The standards will also place the first-ever limits on automobile greenhouse gas emissions, and are expected to reduce emissions by 21 percent by 2030 compared with what the output would have been without the standards．Because emissions from passenger vehicles represent about one-fifth of America’s greenhouse gases, this is a step forward for the planet．

　　The automakers, who fought the rules until they went broke(破产), have come to accept this as a step forward as well．A single national standard provides regulatory certainty, and they’ve got to get more efficient to survive．

　　However, some in Congress seemed determined to roll back the laws that got us here．Senator Lisa Murkowski, a Republican from Alaska, and several other senators have added a challenge to the federal government’s authority to regulate greenhouse gases under the Clean Air Act－not just from automobiles but from other sources．The Supreme Court gave the Environmental Protection Agency that authority three years ago, and the new emissions standards would have been impossible without it．

　　There has also been talk in the Senate of eliminating California’s special authority under the Clean Air Act to set more aggressive motor vehicle standards than the federal limits．California used that authority to pass a law in 2002 setting greenhouse gas emissions limits for cars sold there．It was the first law of its kind in this country, and it provided the drive and the foundation for the new nationwide standards．

　　What all of these opponents mean to do is to roll back history and the hard-won environmental protections it has produced．That would be a huge mistake．

READING COMPREHENSION

　　Schools have banned cupcakes, issued fatness report cards and cleared space in cafeterias for salad bars．Just last month, Michelle Obama’s campaign to end childhood fatness promised to get young people moving more and restore school lunch, and drink makers said they had cut the number of liquid calories shipped to schools by almost 90 percent in the past five years．

　　But new research suggests that interventions(干预)aimed at school-aged children may be, if not too little, too late．

　　More and more evidence points to essential events very early in life－during the child years, babyhood and even before birth, in the womb(胎)－that can set young children on a fatness path that is hard to change by the time they’re in kindergarten．The evidence is not ironclad, but it suggests that prevention efforts should start very early．

　　Among the findings are these：

　　●The fat angel-like baby who is growing so nicely may be growing too much for his or her own good, research suggests．

　　●Babies whose mothers smoked during pregnancy are at risk of becoming fat, even though the babies are usually small at birth．

　　●Babies who sleep less than 12 hours are at increased risk for fatness later．If they don’t sleep enough and also watch two hours or more of TV a day, they are at even greater risk．

　　Some early interventions are already widely practiced．Doctors recommend that overweight women lose weight before pregnancy rather than after, to cut the risk of fatness and diabetes in their children; breast-feeding is also recommended to lower the obesity risk．

　　Like children and teenagers, babies and toddlers have been getting fatter．One in 10 children under age 2 is overweight．The percentage of children ages 2 to 5 who are fat increased to 12.4 percent in 2006 from 5 percent in 1980．But most prevention programs have avioded intervening at very young ages, partly because the school system offers an efficient way to reach large numbers of children, and partly because the rate of fat teenagers is even higher than that of younger children－18 percent．

　　Scientists like Dr．Birch worry about what are called epigenetic changes．The genes taken over from mother and father may be turned on and off and the strength of their effects changed by environmental conditions in early development．Many doctors are concerned about women being fat and unhealthy before pregnancy because the womb is the baby’s first environment．

　　Experts say change may require abandoning some treasured cultural attitudes．“The idea that a big baby is a healthy baby, and a crying baby is probably a hungry baby who should be fed, are things we really need to rethink,”Dr．Birch said．

READING COMPREHENSION

　　A previously unknown kind of human group disappeared from the world so completely that it has left behind the merest piece of evidence that it ever existed－a single bone from the little finger of a child, buried in a cave in the Altai Mountains of southern Siberia．

　　Researchers removed DNA from the bone and reported that it differed obviously from that of both modern humans and of Neanderthals(尼安德特人), living in Europe until the arrival of modern humans on the continent some 44,000 years ago．

　　The child carrying the DNA line was probably 5 to 7 years old, but it is not yet known if it was a boy or a girl．The finger bone was unearthed in 2008 from a place known as the Denisova cave．

　　Researchers are careful not to call the Denisova child a new human species, though it may prove to be so, because the evidence is initial．

　　But the genetic material removed from the bone, found in a layer laid down on the cave floor between 48,000 and 30,000 years ago, belonged to a distinct human line that traveled out of Africa at a different time from the two known ancient human species．Homo erectus(直立人), found in East Asia, left Africa two million years ago, and the ancestor of Neanderthals moved away some 500,000 years ago．The numbers of differences found in the child’s DNA indicate that its ancestors left Africa about one million years ago．

　　The region was inhabited by both Neanderthals and modern humans at that time．Counting the new human line, three human species may have lived together．

　　The standard view has long been that there were three human resettlements out of Africa－those of Homo erectus; of the ancestor of Neanderthals; and finally, some 50,000 years ago, of modern humans．But in 2004, archaeologists reported that they had found the bones of small humans who lived on the Indonesian island of Flores until 13,000 years ago, causing a serious problem to this view．The new line is the second such challenge．

　　If the nuclear DNA of the Denisova child should differ as much as its mitochondrial(线粒体)DNA does from that of Neanderthals and modern humans, the case for declaring it a new species would be strengthened．But it would be unusual for a new species to be recognized on the basis of DNA alone．

　　In new diggings starting this summer, archaeologists will look for remains more analytical than the finger bone．Researchers will also begin re-examining the fossil collections in museums to see if any wrongly assigned bones might belong instead to the new line．

THREE READING COMPREHENSION

　　A plane crash in Western Russian killed Polish President Lech Kaczynski and the other 96 political and military officials on board on April 10．The accident has led to huge national mourning in Poland．But it may provide an opportunity for reconciliation(和解)between Poland and Russia, countries that have a troubled relationship．

　　Many from the political elite were lost in the crash．Beside the president, the dead include the army chief of Staff, the head of National Security Bureau, the national bank president, the deputy foreign minister and other members of parliament．

　　The Polish delegation was heading to Russia to mark the 70 th anniversary of the Katyn Massacre(屠杀)when the accident occurred．In 1940, about 22,000 Polish soldiers, intellectuals, and officials captured after the Soviet Army invaded Poland in 1939, were killed secretly by Soviet police in the forest of Russia’s Katyn．

　　The Katyn Massacre had been a sensitive topic between the countries．The former Soviet Union always denied responsibility for the massacre．It was not until 1992 that Russian released archived documents about the killing．

　　Katyn is merely a short chapter in Poland and Russia’s long and troubled history．In the 18 th century, along with Prussia,(then an important part of Germany)and Austria．Russia participated in three carve－ups of Poland．In 1795, after the third carve－up, the country was erased from the map of Europe．It was in 1918 that Poland regained its independence．But in 1939, at the beginning of the World War II, it was invaded by Germany and the Soviet Union under a secret pact．After the war, Poland became a communist country with close ties to the Soviet Union．

　　In 1989, Poland switched to capitalism and pursued a pro－West position．The most recent tension between the two countries was in 2008．That year, Poland decided to have a US missile shield(导弹防御系统)on its soil, while neighboring Russia threatened to aim missiles at Poland．

　　But the plane crash has created a chance for reconciliation, with Russia sharing the sadness of Poland．Russia has declared April 12 a day of mourning for the victims．Flags flew at half－mast in Moscow．And earlier on April 7, Russia Prime Minister Vladimir Putin became the first Russian leader to mark the anniversary of the massacre．

　　“I think it should improve relations between the two countries, as Russians feel our grief,”said Radek Sikorski, Pland’s foreign minister．

THREE READING COMPREHENSION

　　In a surprising discovery about where higher life can survive, scientists have found a shrimp -like creature and a jellyfish swimming beneath an Antarctic ice sheet．

　　About 180 meters below the ice where no light can get through, scientists had figured nothing much more than a few microbes(微生物)could exist．

　　That’s why a NASA team was surprised when they lowered a video camera to get the first long look at the underbelly of an ice sheet in Antarctica．A curious shrimp－like creature came swimming by and then parked itself on the camera’s cable．Scientists also pulled up a tentacle(触须)they believe came from a jellyfish．

　　“We were operating on the presumption that nothing’s there．”Said NASA ice scientist Robert Bindschadler．“It was a shrimp you’d enjoy having on your plate．”

　　“We were just gaga(狂热的)over it,”he said of the 7.5cm long, orange creature starring in their two－minute video．Technically, it’s not a shrimp．It’s a Lyssianasid amphipod, which is distantly related to the shrimp．

　　The video is likely to inspire experts to rethink what they know about life in harsh environments．And it has scientists thinking that if shrimp－like creatures can live below 180 meters of Antarctic ice in freezing dark water, what about other cold places?What about Europa, a frozen moon of Jupiter?

　　Cynan Ellis－Evans, a scientist of the British Antarctic Survey called the finding fascinating．He said it was possible the creatures swam in from far away and don’t live there permanently．

　　But Kim, who is a co-author of the study, doubts it．“The site in West Antarctica is at least 19 km from open seas．Bindschadler drilled a 20 cm－wide hole and was looking at a tiny amount of water．That means it’s unlikely that two creatures swam from great distances and were captured randomly in that small of an area,”she said．

　　Yet scientist were puzzled at what the food source would be for these creatures．While some microbes can make their own food out of chemicals in the ocean, complex life like the shrimp can’t, Kim said．

　　“So how do they survive?That’s the key question．”Kim Sai．

　　“It’s pretty amazing when you find a huge puzzle like that on a planet where we thought we know everything．”Kim said．

THREE READING COMPREHENSION

　　Next time you find yourself drenched(湿透)in an unexpected heavy rain, look on the bright side－it will be a memorable experience．While wet weather may make us feel gloomy, it sharpens the memory and improves our recall．But those who feel in a good mood because it’s a sunny day are able to remember less well, according to memory tests carried by Australian researchers．

　　Professor Joe Forgas, who led the research, said：“It seems strange but a little bit of sadness is a good thing．People performed much better on our memory test when the weather was unpleasant and they wee in a slightly negative mood．On bright sunny days, when they were more likely to be happy, the flunked it．”

　　The tests were carried out on shoppers at a store in Sydney, where researchers randomly placed ten small objects on the check－out counter．On rainy days, sad music was played in the store．When it was bright and sunny, customers heard cheery music．This was done to further influence them towards negative or positive moods．After shopping, customers were asked how many of the objects they could remember．Their scores were three times higher when the weather was had and they were feeling angry, compared with those tested on sunny days．The results were published in Journal of Experimental Psychology．A report on the findings said：“They point to a growing body of evidence that the way people think, the quality of their judgments and the accuracy of their memory are all significantly influenced by positive and negative moods．”

　　Professor Forgas said,“We found that weather－inducted negative mood improved memory accuracy．Shoppers in a negative mood showed better memory and higher discrimination ability．”

　　A worse mood helped to focus people’s attention on their surroundings and led to a more thorough and careful thinking style, while happiness increased confidence and forgetfulness．

　　Being happy tends to promote a thinking style that is less focused on our surroundings．In a positive mood we are less likely to make more snap(匆忙的)judgments about people we meet．Mild negative mood, in turn, tends to increase attention to our surroundings and produce a more careful, thorough thinking style．

　　Accurately remembering everyday scenes is a difficult task, yet such memories can be on importance in everyday life．Surprisingly, the influence of mood states on the accuracy of real-life memories is still poorly understood．

阅读理解

　　When families gather for Christmas dinner, some will stick to formal traditions dating back to grandma’s generation．Their tables will be set with the good dishes and silver, and the dress code will be Sunday best．

　　But in many other homes, this china-and-silver elegance has given way to a stoneware(粗陶)and stainless informality, with dresses assuming an equally casual-Friday look．For hosts and guests, the change means greater simplicity and comfort．For makers of fine china in Britain, it spells economic hard times．

　　Last week Royal Doulton, the largest employer in Stoke-on-Trent, announced that it is eliminating 1,000 jobs－one-fifth of its total workforce．That brings to more than 4,000 the number of positions lost in 18 months in the pottery(陶瓷)region．Wedgwood and other pottery factories made cuts earlier．

　　Although a strong pound and weak markets in Asia play a role in the downsizing, the layoffs in Stoke have their roots in earthshaking social shifts．A spokesman for Royal Doulton admitted that the company“has been somewhat slow in catching up with the trend”toward casual dining．Families eat together less often, he explained, and more people eat alone, either because they are single or they eat in front of television．

　　Even dinner parties, if they happen at all, have gone casual．In a time of long work hours and demanding family schedules, busy hosts insist, rightly, that it’s better to share a takeout pizza on paper plates in the family room than to wait for the perfect moment or a“real”dinner party．Too often, the perfect moment never comes．Iron a fine-patterned tablecloth?Forget it．Polish the silver?Who has time?

　　Yet the loss of formality has its down side．The fine points of etiquette(礼节)that children might once have learned at the table by observation or instruction from parents and grandparents(“Chew with your mouth closed．”“Keep your elbows off the table．”)must be picked up elsewhere．Some companies now offer etiquette seminars for employees who may be able professionally but inexperienced socially．

阅读理解

　　By far the most common difficulty in study is simple failure to get down to regular concentrated work．This difficulty is much greater for those who do not work to a plan and have no regular routine of study．Many students muddle along, doing a bit of this subject or that, as the mood takes them, or letting their set work pile up until the last possible moment．

　　Few students work to a set timetable．They say that if they did work out a timetable for themselves they would not keep to it, or would have to change it frequently, since they can never predict(foresee)from one day to the next what their activities will be．

　　No doubt some students take much more kindly to a regular routine than others．There are many who shy away from a self-controlled weekly timetable, and dislike being tied down to a fixed programme of work．Many able students state that they work in cycles．When they become interested in a topic they work on it attentively for three or four days at a time．On other days they avoid work completely．It has to be admitted that we do not fully understand the motivation to work．Most people over 25 years of age have become used to a work routine, and the majority of really productive workers set aside regular hours for the more important areas of their work．The“tough-minded”school of workers doesn’t fully accept the idea that good work can only be done naturally, under the influence of inspiration．

　　Those who believe that they need only work and study as the fit takes them have a mistaken belief either in their own talent or in the value of“freedom”．Freedom from control and discipline leads to unhappiness rather than to“self-expression”or“personality development”．Our society insists on regular habits, timekeeping and punctuality(准时), and whether we like it or not, if we mean to make our way in society, we have to meet its demands．

阅读理解

　　Most people would agree that it would be wonderful if humans could regenerate(再生)limbs．Those who have lost their arms or legs would be complete again．The day is still far off when this might happen．But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers．

　　Regeneration is not a newly-discovered process．For centuries, scientists have seen it work in some kinds of animals．Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans．Their experiments show that nerves(神经), cell chemistry and the natural electric currents in the body all seem to have a part in this process．

　　The body of every animal contains general purpose cells that change into whatever kind of cells the body needs．These cells collect around the wound．They form a mass called a blastema(芽基)．The cells of the blastema begin to change．Some became bone cells, some muscle cells, some skin cells．Slowly, a new part re-grows from the body outward．When completed, the new part is just like the old one．

　　More than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals．So do animals lower on the ladder of evolutionary(进化的)development．The major differences seem to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs．

　　Another helpful piece of information was discovered in the late 1800s．Scientists found that when a creature is injured, an electrical current flows around the wound．The strength of the current depends on how severe the wound is and on how much nerve tissue(组织)is present．

阅读理解

　　TOKYO－A child-like robot that combines the roles of nurse, companion and security guard is to go on the market to help the growing ranks of elderly Japanese with no one to look after them．

　　The“Wakamaru”robot can walk around a house 24 hours a day, warning family, hospitals and security firms if it perceives(notices)a problem．It will, for example, call relatives if the owner fails to get out of the bath．

　　Cameras implanted in the“eye-brows”of the robot enable it to“see”as it walks around an apartment．The images can be sent to the latest cellphones, which display the pictures．

　　Mitsubishi Heavy Industries, which developed Wakamaru, plans to start selling the metre-high robots by April, 2005, for about ＄15,000 Cdn．

　　Wakamaru, which speaks with either the voice of a boy or girl, is also designed to provide companionship, greeting its“papa”when he comes home．

　　It is the first household robot able to hold simple conversations, based on a vocabulary of around 10,000 words．It cannot only speak but can understand answers and react accordingly．

　　It will ask“Are you all right?”if its owner does not move for some time．If the answer is no, or there is no answer, it will telephone preset numbers, transmitting images and functioning as a speakerphone．

　　Wakamaru will in form a xecurity firm if ther is a loud bang or if an unknown person enters the house while the owner is out or asleep．It can recognize up to 10 faces．

　　But like nost robots it cannot climb stairs．

　　It can be set to remind forgetful people when it is time to take medicine, eat and sleep．

　　Mitstubishi adapted Wakamaru from robots it already makes to go around nuclear power facilities．The idea to use the technology in the home came from a company employee．

　　The project chief said,“Looking at the ageing of society and the falling birth rate we decide that this could work as a business．We want to offer Wakamaru as a product that helps society．”

　　The technology has gained nation-wide publicity in Japan among increasing xoncern over how to look after the ever-growing number of old people．The life expectancy of Japanese women has shot up to almost 85, the highest in the world．

　　At the same time, extended families are being replaced by nuclear families．This has left many Japanese anxious about their elderly parents, whom they rarely see because of their long hours at the office．