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1.It’s not quite as easy as putting thermometers under their tongues and waiting 30 seconds,but scientists have discovered a way to measure the average body temperature of animals that lived millions of years ago.The findings will help biologists learn more about extinct animals’ physiology and give paleoclimatologists a powerful new tool for gauging ancient environmental temperatures.

2.Where did Earth’s oceans come from? Astronomers have long contended that icy comets and asteroids delivered the water for them during an epoch of heavy bombardment that ended about 3.9 billion years ago.But a new study suggests that Earth supplied its own water,leaching it from the rocks that formed the planet.The finding may help explain why life on Earth appeared so early,and it may indicate that other rocky worlds are also awash in vast seas.

3.California has more than two thousand kinds of plants that are not found anywhere else.A new study says climate change could severely affect these plants by the end of the century.Many could move northward and toward the Pacific coast in reaction to rising temperatures and changes in rainfall.Others might climb up mountains to find the cooler climates they like.But David Ackerly at the University of California,Berkeley,says the speed of climate change is greater than during ice ages in the past.He says plants that cannot move fast enough are in danger of getting killed off before they can relocate.Changes in plants could also affect animals that depend on the plants for food.

4.For the first time,a study has demonstrated that an anti-HIV pill can protect uninfected people from contracting the AIDS virus through sex.The much-anticipated results show that an already approved drug can cut transmission rates nearly in half,which could provide a powerful new tool to curb the AIDS epidemic.“It’s a game changer,” says one of the dozens of clinicians who participated in the study,Kenneth Mayer of Fenway Health in Boston.But experts say the success also raises a dizzying array of complicated issues about human behavior,resources,risk,and public health.

5.Germany’s high court today has upheld the country’s law governing genetically modified (GM) crops.The law,originally passed in 2004 and modified slightly in 2008,holds farmers—and researchers—who plant GM crops liable for any pollen that escapes to neighbors’ fields and makes any crops contaminated this way unmarketable as GM-free.It also requires a buffer zone between GM and conventional crops,and it mandates a public database that includes the locations of all GM plantings.

6.As we age,many of our cells stop dividing.Our organs,no longer able to rejuvenate themselves,slowly fail.Scientists don’t fully understand what triggers this,but many researchers suspect the gradual shrinking of telomeres,the protective DNA caps on the end of chromosomes.A little bit of telomere is lost each time a cell divides,and telomerase,the enzyme that maintains caps,isn’t typically active in adult tissues.Another piece of evidence: People with longer telomeres tend to live longer,healthier lives,whereas those with shorter telomeres suffer more from age-related diseases,such as diabetes,Alzheimer’s,and heart disease.

7.Chad is dirt poor because its dirt is poor.Germany is relatively rich because its soil is rich.That’s the provocative conclusion flowing from a new study,which suggests that just two fundamental factors—soil type and climate—can largely explain why humans have prospered in some places but not in others.The finding,drawn from a computer model originally used to predict the distribution of moths,also may help explain why some regions are more prone to violence than others.

8.Modern mammals are warm-blooded,meaning they maintain a body temperature of about 37˚C,whereas modern cold-blooded animals,such as reptiles,fish,and amphibians,tend to have lower body temperatures that often fluctuate depending on their environments.When this distinction first arose is unclear,though,and researchers have debated whether ancient animals such as dinosaurs and pterosaurs were warm- or cold-blooded.

9.In energy balance physical activity also plays a key role because it uses up calories consumed.Regular physical activity is good for overall health.Physical activity decreases the risk for colon cancer,diabetes,and high blood pressure.It also helps to control weight,contributes to healthy bones,muscles,and joints; reduces falls among the elderly; and helps to relieve the pain of arthritis.Physical activity does not have to be strenuous to be beneficial.Moderate physical activity,such as 30 minutes of brisk walking five or more times a week,also has health benefits.

10.The Federal Trade Commission’s (FTC) call for a “do not track” mechanism to be created to protect Web users’ private information from being exploited by online advertising networks sounds good on paper,but implementing such a technology would be a thorny process.It is not because the technology is so difficult to create,but rather because most of the companies that make Web browsers are supported by or are themselves online advertising networks.

（II）篇章翻译练习

1.It depends on how much proof you want.By the tough standards of modern medicine,there’s little hard evidence for the efficacy of dozens of compounds on the list of the World Anti-Doping Agency(WADA).They are rarely tested in placebo-controlled trials; for most,the evidence is what medical researchers would call “anecdotal”.

Many substances on the list are probably useless,most researchers say,if not outright detrimental for athletic prowess.“The science behind it is pretty weak,” concedes Swedish oncologist Arne Ljungqvist,a former Olympic high jumper who chairs WADA’s Health,Medical & Research Committee.

Not that we don’t know anything about what works.Decades ago,double-blind trials for amphetamines and other stimulants showed that they can enhance performance in short,explosive activities,such as sprinting.Anabolic steroids have been proved beyond any doubt to increase muscle mass and enhance performance among male athletes in sports that require strength,such as weightlifting and shot-putting; in women,they appear to work for endurance sports as well.History provides more circumstantial evidence: In many sports,the amazing rise in performances came to a halt after the crackdown on anabolic steroids began in earnest in the 1980s,and some records have not been broken since then.

But for many other compounds the evidence is thin,says Harm Kuipers,a physician and former speed-skating world champion who studies doping at Maastricht University in the Netherlands.One of the hottest substances of the moment,erythropoietin (EPO),has been tested for performance enhancement in only four double-blind trials,Kuipers says; they showed that it increased maximum oxygen uptake and performance,but apparently for short durations only.

Data are lacking because rigorous trials are expensive,and there’s little incentive to fund them.The drugs’ target population,top athletes,usually can’t be recruited into studies because it might ruin their careers.Also,the list of substances and combinations is endless; cyclists once used a cocktail of strychnine,cognac,and cocaine,for instance.And the risk of side effects can make ethics panels frown.

Still,some say WADA should promote more efficacy studies.The agency is currently spending millions of dollars to improve detection of human growth hormone,a banned substance that appears to be very popular and is very hard to detect.Yet,the “science on efficacy is really soft,” says Donald Catlin,who until 2007 led a major anti-doping lab at the University of California,Los Angeles.“I’d prefer to have true evidence before we go after it.”

If WADA,created in 1999,had a more scientific attitude,it would drop many drugs from the list,which it inherited from the International Olympic Committee,says Kuipers,who sat on the panel for several years.Countless substances—such as beta-agonists,corticosteroids,and narcotics—are listed simply because athletes used them,or were rumored to use them,even though they are widely believed to be useless.

A spot on the list may actually encourage athletes to experiment with a substance,Kuipers says: “The doping list is a shopping list for some.” Such experiments can be dangerous.In healthy people,for instance,an overdose of insulin—another listed substance that few believe does athletes any good—can lead to a fatal drop in blood sugar levels.

Ljungqvist takes the opposite view: Removing substances from the list would signal that it’s okay to use them,he says.And WADA wants to protect athletes from any drug they don’t need,if only to send a message to their young fans.Ljungqvist agrees that this means that practically anything can end up on WADA’s list—and that athletes risk ending their careers by taking something that doesn’t bring them one bit closer to a gold medal.（633 words）

2.In 1960,Ethiopian marathoner Abebe Bikila earned an Olympic gold medal without wearing any shoes.But bare feet on the Olympic track these days are passé,as athletes slip into ever more high-tech gear.Shoes,swimsuits,and clothing are getting lighter and stronger,adhering like glue to athletes’ bodies and moving more fluidly through air and water.

In Beijing,U.S.track and field athletes will be wearing Nike shoes and clothing that incorporate threads made of Vectran,a superstrong liquid crystal polymer that withstands high temperatures.The result,according to Nike,is lighter,stiffer shoes to reduce friction and clothes that reduce drag by 7% compared with the Nike outfits worn at the 2004 games in Athens.

Sprinters will also benefit from even tighter compression garments.In theory,these improve performance because of proprioception,that unconscious ability that enables you to pinpoint your nose when your eyes are closed.Physiologist Russ Tucker of the University of Cape Town,South Africa,says that because runners need to contract muscles precisely—at the proper angle,velocity,and time—tight-fitting garments help the brain identify where in space the limb is poised so they know when to activate the muscle.

In the water,the Speedo LZR Racer suit,which debuted in March 2008,is all the buzz.Swimmers donning the suit have broken 46 world records so far.The suit includes polyurethane panels placed strategically around parts of the torso,abdomen,and lower back that experience high amounts of drag in the pool.It also incorporates a corset-like structure that keeps the body in a streamlined position.Raúl Arellano,a biomechanist the University of Granada,Spain,says the LZR Racer suit could benefit older athletes like 41-year-old Dara Torres of the United States,especially in areas where fat tends to accumulate.

Some of the technologies needed to develop the suit “didn’t really exist 10 years ago,”says Jason Rance,head of Aqualab in Nottingham,U.K.,the division of Speedo that designed the suit.Those include ultrasonic welding that eliminated the need for seams,and technology that allowed parts of the suit to be finely sanded and a water-repellent substance added to prevent water from leaking in.

But the suit has raised eyebrows.“Who’s going to win the gold medal,the swimmer or the technician?” asks Huub Toussaint,a biomechanist at the Free University in Amsterdam,who worries that the suit gives swimmers an unfair edge,although the international body governing the sport approved it.

For all the hype surrounding space-age shoes and clothing,there’s a flip side: Any boost to performance could just be psychological.South Africa’s Tucker,who races for fun,says the compression garments make him feel powerful and secure.Such a superhero aura might give any competitor a mental edge.“It doesn’t really matter if the advantages are physically real or not,” he says,“as long as the athlete gets some benefit.”　(506 words)