2019年6月大学英语六级考试真题第3套Listening Comprehension(30 minutes)特别说明六级考试每次仅考两套听力第三套听力试题同第一套或第二套试题一致PartⅢReading Comprehension(40 minutes)Section ADirections:In this section,there is a passage with ten blanks.You are required to select one word foreach blank from a list of choices given in a word bank following the passage.Read thepassage through carefully before making your choices.Each choice in the bank is identifiedby a letter.Please mark the corresponding letter for each item on Answer Sheet 2 with asingle line through the centre.You may not use any of the words in the bank more thanonce.Steel is valued for its reliability,but not when it gets cold.Most forms of steel 26 becomebrittle (at temperatures below about-25C unless they are mixed with other metals.Now,though,a novel type of steel has been developed that resists 27 at much lower temperatures,while remaining its strength and toughness-without the need for expensive 28Steel's fragility at low temperatures first became a major concern during the Second World War.After German U-boats torpedoed(用鱼雷攻击)numerous British ships,,a27O0-strong fleet of cheap-and-cheerful "Liberty ships"was introduced to replace the lost vessels,providing a lifeline for the29 British.But the steel shells of hundreds of the ships 30 in the icy north Atlantic,and 12broke in half and sank.Brittleness remains a problem when building steel structures in cold conditions,such as oil rigsin the Arctic.So scientists have 31 to find a solution by mixing it with expensive metals such asnickel.Yuuji Kimura and colleagues in Japan tried a more physical 32.Rather than adding othermetals,they developed a complex mechanical process involving repeated heating and very severemechanical deformation,known as tempforming.The resulting steel appears to achieve a combination of strength and toughness that is 33 tothat of modern steels that are very rich in alloy content and,therefore,very expensive.Kimura's team intends to use its tempformed steel to make ultra-high strength parts,such asbolts.They hope to reduce both the number of 34 needed in a construction job and theirweight-by replacing solid supports with 35 tubes,for example.This could reduce the amountof steel needed to make everything from automobiles to buildings and bridges.6·1A)abruptlyDcrackedB)additivesJfracturesapproachK)hollowD)ardentlyL)relevantE)besiegedM)reshuffledF)channelN)strivedGcomparableO)violentHcomponentsSection BDirections:In this section,you are going to read a passage with ten statements attached to it.Eachstatement contains information given in one of the paragraphs.Identify the paragraph fromwhich the information is derived.You may choose a paragraph more than once.Eachparagraph is marked with a letter.Answer the questions by marking the corresponding letteron Answer Sheet 2.The future of personal satellite technology is here-are we ready for it?[A]Satellites used to be the exclusive playthings of rich governments and wealthy corporations.Butincreasingly,as space becomes more democratized,they are coming within reach of ordinarypeople.Just like drones()before them,miniature satellites are beginning to fundamentallytransform our conceptions of who gets to do what up above our heads.[B]As a recent report from the National Academy of Sciences highlights,these satellites holdtremendous potential for making satellite-based science more accessible than ever before.However,as the cost of getting your own satellite in orbit drops sharply,the risks of irresponsible use grow.The question here is no longer“Can we?”but“Should we?”What are the potential downsidesof having a slice of space densely populated by equipment built by people not traditionallylabeled as "professionals"?And what would the responsible and beneficial development and useof this technology actually look like?Some of the answers may come from a nonprofitorganization that has been building and launching amateur satellites for nearly 50 years[C]Having your personal satellite launched into orbit might sound like an idea straight out of sciencefiction.But over the past few decades a unique class of satellites has been created that fits the bill:CubeSats.The "Cube"here simply refers to the satellite's shape.The most common CubeSat is a10 cm cube,so small that a single CubeSat could easily be mistaken for a paperweight on yourdesk.These mini-satellites can fit in a launch vehicle's formerly "wasted space."Multiples can bedeployed in combination for more complex missions than could be achieved by one CubeSat alone.6[D]Within their compact bodies these minute satellites are able to house sensors and communicationsreceivers/transmitters that enable operators to study Earth from space,as well as space aroundEarth.They're primarily designed for Low Earth Orbit (LEO)an easily accessible region ofspace from around 200 to 800 miles above Earth,where human-tended missions like the HubbleSpace Telescope and the International Space Station (ISS)hang out.But they can attain moredistant orbits;NASA plans for most of its future Earth-escaping payloads(to the moon and Marsespecially)to carry CubeSats[E]Because they're so small and light,it costs much less to get a CubeSat into Earth's orbit than atraditional communications or GPS satellite.For instance,a research group here at Arizona StateUniversity recently claimed their developmental small CubeSats could cost as little as $3,000 toput in orbit.This decrease in cost allows researchers,hobbyists and even elementary schoolgroups to put simple instruments into LEO or even having them deployed from the ISS.[F]The first CubeSat was created in the early 2000s,as a way of enabling Stanford graduate studentsto design,build,test and operate a spacecraft with similar capabilities to the USSR's Sputnik联的人造卫星).Since then,NASA,the National Reconnaissance Office and even Boeing haveall launched and operated CubeSats.There are more than 130 currently in operation.The NASAEducational Launch of Nano Satellite program,which offers free launches for educational groupsand science missions,is now open to U.S.nonprofit corporations as well.Clearly,satellites arenot just for rocket scientists anymore.[G]The National Academy of Sciences report emphasizes CubeSats'importance in scientificdiscovery and the training of future space scientists and engineers.Yet it also acknowledges thatwidespread deployment of LEO CubeSats isn't risk-free.The greatest concern the authors raise isspace debris-pieces of "junk"that orbit the earth,with the potential to cause serious damage ifthey collide with operational units,including the ISS.[H]Currently,there aren't many CubeSats and they're tracked closely.Yet as LEO opens up to moreamateur satellites,they may pose an increasing threat.As the report authors point out,even near-misses might lead to the "creation of a burdensome regulatory framework and affect the futuredisposition of science CubeSats."[I]CubeSat researchers suggest that now's the time to ponder unexpected and unintended possibleconsequences of more people than ever having access to their own small slice of space.In an erawhen you can simply buy a CubeSat kit off the shelf,how can we trust the satellites over ourheads were developed with good intentions by people who knew what they were doing?Some"expert amateurs"in the satellite game could provide some inspiration for how to proceedresponsibly.6