第4部分：阅读理解(第3l一45题，每题3分，共45分)

　　下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。

　　第一篇

Arctic Melt

　　Earth's North and South Poles ale famous for being cold and icy．Last year，however，theamount of ice in the Arctic Ocean feU t0 a record low．

　　Normally，ice builds in Arctic waters around the North Pole each winter and shrinks during thesummer．But for many years，the amount of ice left by the end of summer has been declining．

　　Since 1979，each decade has seen an 11．4 percent drop in end of summer ice cover．Between1981 and 2000，ice in the Arctic lost 22 percent of its thickness，becoming 1．13 meters thinner．

　　Last summer，Arctic sea ice reached its skimpiest levels yet．By the end of summer 2007，theice had shrunk to cover iust 4．2 million square kilometers．That's 38 percent less area than the average cover at that time of year．And it's a very large 23 percent below the previous record low，whichwas set just 2 years ago．This continuing trend has scientists concerned．

　　There may be several reasons for the ice melt，says Jinlun Zhang，an oceanographer at the University of Washington at Seattle．Unusually strong winds blew through the Arctic last summer．Thewinds pushed much of the ice out of the central Arctic．leaving a large area of thin ice and open water．

　　Scientists also suspect that fewer clouds cover the Arctic now than in the past．Clearer skies allow more sunlight to reach the ocean．The extra heat warnls both the water and the atmosphere．Inparts of the Arctic Ocean last year，surface temperatures were 3．5℃ warmer than average and 1．5℃warmer than the previous record high．

　　With both air and water getting warmer，the ice is melting from both above and below．In someDarts 0f the Beaufort Sea，north of Alaska and western Canada，ice that measured 3．3 meters thickat the beginning of the summer measured just 50 centimeters by season's end．

　　The new measurements suggest that melting is far more severe than scientists have seen by justlooking at ice cover from above，says Donald K．Perovich，a geophysicist at the U．S．Army ColdRegions Research and Engineering Laboratory in Hanover，N．H．

　　Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover．

　　31．Which of the following is closest in meaning to the word"build"in the first sentence of the second paragraph?

　　A．construct

　　B．extend

　　C．create

　　D．expand

　　32．What is the ice cover in the Arctic by the end of 2007 summer?

　　A．4．2 million square kilometers

　　B．11．4 million square kilometers

　　C．1．13 million square kilometers

　　D．38 million square kilometers

　　33．What are the reasons for the ice melting according to the scientists?

　　A．strong winds and clear skies

　　B．long summer and short winter

　　C．open water and thin ice

　　D．light clouds and light winds

　　34．Why is the ice melting from both above and below?

　　A．Because extra heat warms the air．

　　B．Because extra heat warms the water．

　　C．Because the temperature above the water is higher．

　　D. Rnth A and B．

　　35．What can be a possible title for the passage?

　　A．What are scientists looking for in the Arctic Ocean?

　　B．What are scientists doing in the Arctic Ocean?

　　C．Why are scientists worrying about the Arctic Ocean?

　　D．Why are scientists interested in the Arctic Ocean?

　　第二篇

　　Citizen Scientists

　　Understanding how nature responds to climate change will require monitoring key life cycleevent-flowering，the appearance of leaves，the first frog calls of the spring all around the world．

　　But ecologists can't be everywhere so they're turning to non-scientists，sometimes called citizen scientists，for help．

　　CIimate scientists are not present everywhere．Because there are so many places in the worldand not enough scientists to observe all of them，they're asking for your help in observing signs ofclimate change across the world．The citizen scientist movement encourages ordinary people too bserve a very specific research interest-birds，trees，flowers budding，etc．and send their observationsto a giant database to be observed by professional scientists．This helps a small number of scientiststrack a large amount of data that they would never be able to gather on their own．Much like citizenjournalists helping large publications cover a hyper-local beat，citizen scientists are ready for theconditions where thev live． All that's needed to become one is a few minutes each day or each weekto gather data and send it in．

　　A group of scientists and educators launched an organization last year called the National Phenology Network．"Phenology"is what scientists call the study of the timing of events in nature.

　　One of the group's first efforts relies on scientists and non-scientists alike to collect data about plant flowering and leafing every year．The program，called Projeet BudBurst，collects life cycle da. ta on a variety of common plants from across the United States．People participating in the projectwhich is open to everyone record their observations on the Project BudBurst website．

　　"People don't have to be plant experts，they just have to look around and see what's in their neighborhood，"says Jennifer Schwartz，an education consultant with the project．"As we collectthis data．we'll be able to make an estimate of how plants and communities of plants and animals will respond as the climate changes．"

　　36．Ecologists turn to non-scientist citizens for help because they need them__________________．

　　A．to provide their personal life cycles

　　B．to observe the life cycle of plants

　　C．to collect data of the life cycle of living things

　　D．to teach children knowledge about climate change

　　37．What are citizen scientists asked to do?

　　A．To develop a specific research interest and become professional scientists．

　　B．To send their research observations to a professional database．

　　C．To increase their knowledge about climate change．

　　D．To keep a record of their research observations．

　　38．In"All that，s needed to become one…(paragraph2)"，what does the word"one"stands for?

　　A．a citizen journalist

　　B．a citizen scientist

　　C．a scientist

　　D．a citizen

　　39．What is NOT true of Project BudBurst?

　　A．Only experts can participate in it．

　　B．Everybody can participate in it．

　　C．It collects life cycle data on a variety of common plants．

　　D．It has its own website．

　　40．What is the final purpose of Project BudBurst?

　　A．To study when plants will have their first buds．

　　B．To find out the types of plants in the neighborhood．

　　C．To collect life cycle data on a variety of common plants from across the United States．

　　D．To investigate how plants and animals will respond as the climate changes．

　　第三篇

Rockets in the Sky

　　If someone asked you．"What color is the sky?"I expect that you would answer，"Blue．"I amafraid that you would be wrong．The sky has no color．When we see blue，we are looking at bluesunlight．The sunlight is shining on little bits of dust in the air．

　　We know that there is air all around the world．We could not breathe without air．Airplanescoutd not fly without air．They need air to lift their wings．Airplanes cannot fly very high because asthey go higher the air gets thinner．If we go far enough away from the earth，we find there is no air. What is the sky?The sky is space．In this space there is nothing except the sun，the moon andall the stars．

　　Scientists have always wanted to know more about the other worlds in the space．They havelooked at them through telescopes and in this way they have found out a great deal．

　　The moon is about 384．000 kilometers away from the earth．An airplane cannot fly to the moonbut there is a thing that can fly even when there is no air．This is rocket．

　　I am sure that you are asking．"How does a rocket fly?"If you want to know，get a balloon andthen blow it up until it is quite big．Do not tie up the neck of the balloon．Let go!The balloon willfly off through the air very quickly．The air inside the balloon tries to get out．It rushes out through neck 0f the ballOOfl and this pushes the balloon through the air．It does not need wings like an air. plane．

　　This is how a rocket works．It is not made of rubber like a balloon，of course．It is made ofmetal．The metal must not be heavy but it must be very strong．There is gas inside the rocket whichis made very hot．When it rushes out of the end of the rocket，the rocket is pushed up into the air．

　　Rockets can fly far out into space．Rockets with men inside them have already reached themoon．Several rockets，without men inside them，have been sent to other worlds much farther away．

　　One day rockets may be able to go anywhere in the space．

　　41．What color is the sky?

　　A．It iS blue． B．It iS white．

　　C．It is grey．D．It has no color．

　　42．When an airplane flies too high，___________.

　　A．the air will be too thin to support its wings．

　　B．the air will become thicker．

　　C．the air will exert pressure on it．

　　D．the air will disappear in no time．

　　4 3．A rocket can fly to the moon because__________

　　A．it looks like a balloon．

　　B．it is much lighter than an airplane．

　　C．it doesn't have wings．

　　D．it works like an untied balloon．

　　44．Which of the following statements about a rocket is NOT true?

　　A．It can fly when there is no air．

　　B．It can fly without wings．

　　C．It is made of strong metal．

　　D．It is propelled by burning gas inside it．

　　45．A rocket is pushed up into the air when__________

　　A．hot gas rushes out of its head．

　　B．it is powered by gas．

　　C．hot gas rushes out of its bottom．

　　D．hot gas rushes out of its neck．

　　同时按下Crtl键和A键查看答案
第一篇
31．D 32．A 33．A 34．D 35．C 
第二篇
36．C 37．B 38．B 39．A 40．D 
第三篇
41．D 42．A 43．D 44．D 45．C

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