职称英语理工类a级补全短文.doc

四、补全短文（一）Mobile phones（移动电话）Mobile phones should carry a label if they proved' to be a dangerous source of radiation, according to Robert Bell, a scientist. And no more mobile phone transmitter towers should be built until the long-term health effects of the electromagnetic radiation they emit are scientifically evaluated, he said. "Nobody's going to drop dead overnight but we should be asking for more scientific information," Robert Bell said at a conference on the health effects of low-level radiation（1）A report widely circulated among the public says that up to now scientists do not really know enough to guarantee there are no ill-effects on humans from electromagnetic radiation. According to Robert Bell, there are 3. 3 million mobile phones in Australia alone and they are increasing by 2,000 a day（2） AS well, there are 2,000 transmitter towers around Australia, many in high density residential areas. （3） The electromagnetic radiation emitted from these towers may have already produced some harmful effects on the health of the residents nearby.Robert Bell suggests that until more research is completed the Government should ban construction of phone towers from within a 500 metre radius of school grounds, child care centres, hospitals, sports playing fields and residential areas with a high percentage of children（4） He adds that there is also evidence that if cancer sufferers are subjected to electromagnetic waves the growth rate of the disease accelerates.（5）According to Robert Bell, it is reasonable for the major telephone companies to fund it. Besides, he also urges the Government to set up a wide-ranging inquiry into possible health effects. A He says there is emerging evidence that children absorb low-level radiation at a rate more than three times that of adults. B By the year 20004 it is estimated that Australia will have 8 million mobile phones: nearly one for every two people: C "If mobile phones' are found to be dangerous, they should carry a warning label' until proper shields can be devised," he said.D Then who finances the research? E For example, Telstra, Optus and Vodaphone build their towers where it is geographically suit-able to them and disregard the need of the community. F The conclusion is that mobile phones brings more harm than benefit（C、B、E、A、D）（二）The worlds longest bridge（世界上最长的桥）Rumor has it that' a legendary six-headed monster lurks in the deep waters of the Tyrrhenian Sea between Italy and the island of Sicily.（1）When completed in 2010, the world's longest bridge will weigh nearly 300,000 tons - equivalent to the iceberg that sank the Titanic and stretch 5 kilometers long. "That's nearly 50 percent longer than any other bridge ever built,'' says structural engineer Shane Rixon.（2）They're suspension bridges, massive structures built to span vast water channels or. A suspension bridge needs just two towers to shoulder the structure's mammoth weight, thanks to hefty supporting cables slung between the towers and anchored firmly in deep pools of cement at each end of the bridge. The Messina Strait Bridge will have two 54,100-ton towers, which will support most of the bridge's load. The beefy cables of the bridge, each 1. 2 meter in diameter, will hold up the longest and widest bridge deck ever built.When construction begins on the Messina Strait Bridge in 2005, the first job will be to erect370 meter-tall steel towers（3）Getting these cables up will be something'. It's not just their, length - totally 5. 3 kilometers but their weight（4）After lowering vertical " suspender" cables from the main cables, builders will erect a 60-me-wide 54,630-ton steel roadway, or deck - wide enough to accommodate 12 lanes of traffic. deck's weight will pull down on the cables with a force of 70,500 tons. In return, the cables yank up against their firmly rooted anchors with a force of 139,000 tons - equivalent to the weight of about 100,000 cars. Those anchors are essential（5）A Some environmentalists are against the project on biological grounds. B What do the world's longest bridges have in common?C If true, one day you might spy the beast while zipping across the Messina StraitBridge.D They're what will keep the bridge from going anywhere. E The second job will be to pull two sets of steel cables across the strait, each set being a bundle of 44,352 individual steel wires. F They will tip up the scales at 166,500 tons - more than half the bridge's total mass.(C、B、E、F、D)（三）Reinventing the table（重新发明元素周期表）An earth scientist has rejigged the periodic table' to make chemistry simpler to teach to students. (1) But Bruce Railsback from the University of Georgia says he is the first to create a table that breaks with tradition and shows the ions of each element rather than just the elements themselves."I got tired of breaking my arms trying to explain the periodic table to earth students," he says, criss-crossing his hands in the air and pointing to different bits of a traditional table.（2）But he has added' contour lines to charge density, helping to explain which ions react with which."Geochemists just want an intuitive sense of what's going on with the elements, "says Albert from the University of Cambridge.（3） （4）He explains that sulphur, for example, shows up in three different spots - one for sulphide, which is found in minerals, one for sulphite, and one for sulphate, which is found in sea salt, for instance.He has also included symbols to show which ions are nutrients, and which are common in soil or water.（5）A There have been many attempts to redesign the periodic table since Dmitri Mendeleev drew it up in 1871.B Railsback has still ordered the elements according to the number of protons they have.C "I imagine this would be good for undergraduates.D "Railsback has listed some elements more than once.E And the size of element's symbol reflects how much of it is found in the Earth's crust.F The traditional periodic table was well drawn.（A、B、C、D、E）（四）The Bilingual Brain（双语大脑）A But their use of Broca's area was different.B One group consisted of those who had learned a second language as children.C How does Hirsch explain this difference?D We use special parts of the brain for language learning.E And that is very different from learning a language in a high school or college class.F Their work led to an important discovery.（F、B、A、C、E）（五）A Record-Breaking Rover NASAs Mars rover Opportunity has boldly gone where no rover has gone beforeat least in terms of distance. _1_On July 27, after years of moving about on Martian ground, the golf-cart-sized Opportunity had driven more than 24 miles, beating the previous record holdera Soviet rover sent to the moon in 1973. “This is so remarkable considering Opportunity was intended to drive about 1 kilometer and was never designed for distance,” says John Callas, the Mars Exploration Rover Project Manager. _2_ “But what is really importantly is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance.” OPPORTUNITY The solar-powered Opportunity and its twin rover, Spirit, landed on Mars 10 years ago on a mission expected to last 3 months. _3_Spirit stopped communicating with Earth in March 2010, a few months after it got stuck in a sand pit. But Opportunity has continued to collect and analyze Martian soil and rocks. During its mission, Opportunity has captured, and sent back to Earth, some 187,000 panoramic and microscopic images of Mars with its cameras. _4_MARATHON ROVER The rover doesnt seem to be ready to stop just yet. If Opportunity can continue on, it will reach another major investigation site when its odometer hits 26.2 miles. _5_Researchers believe that clay minerals exposed near Marathon Valley could hold clues to Marss ancient environment1. Opportunitys continuing travels will also help researchers as they plan for an eventual human mission to the Red Planet.A It has also provided scientists with data on the planets atmosphere, soil, rocks, and terrain. B He works at NASAs Jet Propulsion Laboratory in Pasadena, California. C Scientists call this site Marathon Valley, because when the rover reaches the area, it will have traveled the same distance as the length of a marathon since its arrival on Mars. D Opportunity has been working on Mars since January 2004. E The objective of the rovers was to help scientists learn more about the planet and to search for signs of lifesuch as the possible presence of water. F Since arriving on the Red Planet in 2004, Opportunity has traveled 25.01 miles, more than any other wheeled vehicle has on another world.（F、B、E 、A、C）（六）Dung to death（施肥致死）Fields across Europe are contaminated with dangerous levels of the antibiotics given to farm animals. The drugs, which are in manure sprayed onto fields as fertilizers, could be getting into our food and water, helping to create a new generation of antibiotic-resistant "superbugs". The warning comes from a researcher in Switzerland who looked at levels of the drugs in farm. （1） Some 120,000 tons of antibiotics are used in the European Union and the US each year. More than half are given to farm-animals to prevent disease and promote growth.（2）Most researchers assumed that humans become infected with the resistant strains by eating contaminated meat.3 But far more of the drugs end up in manure than in meat products, says Stephen Mueller of the Swiss Federal Institute for Environmental Science and Technology in Dubendorf.（3）With millions of tons of animals manure spread onto fields of crops such as wheat and barley each year, this pathway seems an equally likely route for spreading resistance, he said. The drugs contaminate the crops, which are then eaten.（4）Mueller is particularly concerned about a group of antibiotics called sulphonamides. （5） His analysis found that Swiss farm manure contains a high percentage of sulphonamides; each hectare of field could be contaminated with up to 1 kilogram of the drugs. This concentration is high enough to trigger the development of resistance among bacteria. But vets are not treating the issue seriously.There is growing concern at the extent to which drugs, including antibiotics, are polluting the environment. Many drugs given to humans are also excreted unchanged and are not broken down by conventional sewage treatment.A They do not easily degrade or dissolve in water.B And manure contains especially high levels of bugs that are resistant to antibiotics, he says.C Animal antibiotics is still an area to which insufficient attention has been paid. D But recent research has found a direct 0link between the increased use of these farmyard drugs and the appearance of antibiotic-resistant bugs that infect people. E His findings are particularly shocking because Switzerland is one of the few countries to have banned antibiotics as growth promoters in animal feed. F They could also be leaching into tap water pumped from rocks beneath fertilized fields（E、D、B、F、A） （七）Time in the animal world（动物界中的时间）Rhythm controls everything in Nature.（1） The sun provides a basic time rhythm for all living creatures including humans. Nearly all animals are influenced by sun cycles and have developed a biological clock in their bodies following these cycles. The moon also exerts its force and influence on the sea. Its gravitational attraction causes the rising of the tide. （2）When the moon is behind the Earth, centrifugal force cause the second tide of the day.Animals living in tidal areas must have the instinct of predicting these changes, to avoid being stranded and dying of dehydration. Since the time of the dinosaurs, the king crab has been laying eggs at the seaside in a set way. To avoid predator fish 3 , the eggs are always far from seawater and protected by sand. In the following two months, the eggs undergo dramatic changes related to the cycles of the moon. When the second spring tide comes, the young king crabs have matured.（3）Most of the mammals, either the giant-elephant or the small shrew, have the same average total number of heartbeats in their lifetime. Shrews live only for two and a half years, and spend their life at a high speed and high tempo. Animals like shrews with a pulse rate of 600 per minute have an average total of eight. hundred million heartbeats throughout their life The African elephant has a pulse rate of 25 beats per minute, and a life span 6 of 60 years. The size of the body determines the speed of life.（4）As we get older, our sense of time is being influenced by the physiological changes of our body. The elderly spend more time resting, and do few sports（5） For a child, a week is seen as a long time.A For an adult; 'time goes fast year by year.,B It 'controls, for example, the flapping of birds' wings, the beating of the heart and the rising and setting of the sun. C The larger the animal is, the longer its life span is and the slower its life tempo isD The tide goes out when the moon moves away and its attraction is weaker. E We always tend to think' all the animals have the same sense of time as human beings. F The second spring tide takes them back to the sea.（B、D、F、C、A）（八）Watching Microcurrents flow（观察微电流流程）We can now watch electricity as it flows through even the tiniest circuits. By scanning the magnetic field generated as electric .currents flow through objects, physicists have managed（1）The technology will allow manufacturers to scan microchips for faults, as well as revealing microscopic defects in anything from aircraft to banknotes.Xiao and Ben Schrag at Brown University in Providence, Rhode Island, visualize the current by measuring subtle changes in the magnetic field of an object and （2）Their sensor is adapted' from an existing piece of technology that is used to measure large magnetic fields in computer hard drives. " We redesigned the magnetic sensor to make it capable of measuring very weak changes in magnetic fields," says Xiao.The resulting device is capable of detecting a current as weak as 10 microamperes, even when wire is buried deep within a chip, and it shows up features as small as 40 nanometers across. At present, engineers looking for defects in a chip have to peel off the layers and examine the circuits visually; this is one of the obstacles （3） But the new magnetic microscope is sensitive enough to look inside chips and reveal faults such as short circuits, nicks in the wires or electro migration where a dense area of current picks up surrounding atoms and moves them along. "It is like watching a river flow," explains Xiao.As well as scanning tiny circuits, the microscope can be used to reveal the internal structure of any object c