http://www.123zcyy.com/shiti/59.html
F.Natural gas consumption
27.Natural gas is stored deep________.
28.Natural gas is recognized as the most economical energy source_________.
29.When manufacturing many products,people commonly use natural gas____________. 30.It is estimated that by 2025 that natural gas demand in the United States will increase_________. A.over the past 50 years B.beneath the earth surface C.by more than 50 percent D.for more than four decades E.as a raw material F.for home energy needs
第4部分:阅读理解(第3l~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
How the First Stars in the Universe Came into Existence
How the first stars formed from this dust and gas has been a burning question for years,but a state-of-the-art computer simulation now offers the most detailed picture yet of how these first stars in the universe came into existence,researchers say.
The composition of the early universe was quite different from that of today,and the physics that governed the early universe were also somewhat simpler.Dr.Naoki Yoshida and colleagues in Japan and the U.S.incorporated these conditions of the early universe,sometimes referred to as the \dark ages,\simulate the formation of an astronomical object that would eventually shine its light into this darkness.
The result is a detailed description of the formation of a protostar-the early stage of a massive primordial star of our universe,and the researchers'computer simulation,which has been called a \.\.The question of how the first stars evolved is so important because their formations and eventual explo-sions provided the seeds for subsequent stars to come into being.www.Examda.CoM考试就上考试大
According to their simulation,gravity acted on minute density variations in matter,gases,and the mysterious\of a star-a protostar with a mass of just one percent of our sun.The simulation reveals how pre-stellar gases would have actually evolved under the simpler physics of the early universe to form this protostar.
Dr.Yoshida's simulation also shows that the protostar would likely evolve into a massive star capableof synthesizing heavy elements,not just in later generations of stars,but soon after the Big
http://www.123zcyy.com/shiti/59.html
Bang.
\,and the ability to compare how stellar objects form in different time periods and regions of the universe,will eventually allow investigation into the originsof life and planets,\,a Professor of Astronomy at Harvard University and a coauthor of this latest report.\stars haveaccumulated,\,\these ele. ments further across the universe.So when you think about it.a11 of the elements in our bodies originally formed from nuclear reactions in the centers of stars,long ago.\
Their simulation of the birth of a protostar in the early universe signifies a key step toward theambitious goal of piecing together the formation of an entire primordial star and of predicting the massand properties of these first stars of the universe.More powerful computers,more physical data,andan even larger range will be needed for further calculations and simulations,but these researchers hope to eventually extend this simulation to the point of nuclear reaction in.itiation-when a stellar ob. ject becomes a true star.
\.Yoshida has taken the study of primordial star formation to a new level with this simulation,but it still gets us only to the halfway point towards our final goal.It is like laying the foundation of a skyscraper,\Volker Bromm,Assistant Professor of Astronomy at the University of Tex. as,Austin and the author of a companion article.\studies in this area to un-derstand how the initially tiny protostar grows,layer by layer,to eventually form a massive star.Buthere,the physics become much more complicated and even more computational resources are needed.\
31.According to the first two paragraphs,the early universe_______. A.was governed by simpler physics B.got fewer stars shinning in it C.started over 13 billion years ago
D.was composed in a way similar to that of today
32.What can the state-of-the.art computer simulation tell us about? A.How the Big Bang occurred about 13 billion years ago. B.How\.
C.How dust grains and gases were formed after the Big Bang. D.How the first stars canle into being after the Big Bang. 33.What does the\ A.cosmic dark ages. B.dust grains and gases. C.a protostar. D.the early universe.
34.According to paragraph 4,what is NOT true about a protostar? A.It developed into a massive star during the Big Bang.
http://www.123zcyy.com/shiti/59.html
B.It evolved from pre-stellar gases.
C.It was able to integrate heavy elements when evolving into a massive star. D.It had a mass of one percent of the sun.
35.According to the last paragraph,all of the following are goals of the simulation project EXCEPT
A.to know more about the mass and properties of the first stars of the universe B.to simulate the process of how the early universe began C.to apply the simulation to the study of nuclear reaction initiation D.to discover the truth about the formation of a protostar 第二篇 The Iceman
On a September,day in 1991,two Germans were climbing the mountain between Austra and Ita. 1y.High up on a mountain pass,they found the body of a man lying on the ice.At that height (10,499 feet,or 3,200 meters),the ice is usually permanent,but 1991 had been an especially warm year.The mountain ice had melted more than iust usual and so the body had come to the surface.It was lying face downward.The skeleton(骨架)was in perfect condition except a wound on the head.remains of some clothes.The hands were still holding the wooden handle of an ax and on the feet there were very simple leather and cloth boots.Nearby was a pair of gloves made of tree bark (树皮)and a holder for arrows.
Who was the man?How and when had he died?Everybody had a different answer to these questions.Some people thought that it was from this century,perhaps the body of a soldier who died in World War I,since several soldiers had already been found in this area.A Swiss woman who believed it might be her father,who had died in those mountains twenty years before and whose body had never been found.The scientists who rushed to look at the body thought it was probably much older,maybe even a thousand years old.
With modem dating techniques,the scientists soon learned that the iceman was about 5,300 years old.Born in about 3300 B.C.,he lived during the Bronze Age in Europe.At first scientists thought he was probably a hunter who had died from an accident in the high mountains.More recent evidence,however,tells a different story.A new kind of X-ray shows an arrowhead still stuck in his shoulder.It left only a tiny hole in his skin,but it caused internal damage and bleeding.He almost certainly died from this wound,and not from the wound oil the back of his head.This means that he was probably in some kind of battle.It may have been part oi a large war,or he may have beenfightiing bandits.He may even have been a bandit himself. By studying his clothes and tools,scientists have already learned a great deal from the Iceman about the times he lived in.we may never know the full story of how he died,but he has given usimportant clues to the history of those distant times.
36.The body of the iceman was found in the mountains mainly because_________. A.he was lying on the ice
B.two Germans were climbing mountains
http://www.123zcyy.com/shiti/59.html
C.the melted ice made him visible D.he was just on a mountain pass 37.What can be inferred from paragraph 2? A.The iceman was killed while working.
B.The iceman could have died from the wound in the head. C.The iceman lived a poor life.
D.The iceman was struck dead from behind.
38.All the following are assumptions once made about iceman EXCEPT_____________. A.he was a soldier in World War I B.he came from Italy
C.he was a Swiss woman's long-lost father D.He was born about a thousand years ago
39.The scientists made the deduction that the iceman_________. A.was hit in the shoulder by an arrowhead B.was probably in some kind of a battle C.had got a wound on the back of his head D.has a tiny hole in his skin causing his death.
40.The word\. A.robbers B.soldiers C hunters D.shooters 第三篇
Scientists Make Sweet Discovering
Good news for chocoholics:the treat preferred by millions all over the world is good for you, according to American researchers at the University of California.Chocolate contains substancescalled flavonoids that can help maintain a healthy heart and good circulation.The researchers havediscovered that cocoa acts like aspirin and that eating a bar of chocolate has also been shown to release endorphins in the body:these chemicals help to reduce pain and stress and make you feel happy.
The Olmec Indians of Mexico and Central America were the first to grow cocoa beans,in about1500 BC,and the Mayas were drinking unsweetened coca hundreds of years before it became fashionable in Europe.
In 1544,a delegation of Mayan nobles visited Philip of Spain and gave him jars of cocoa as a gift.Cocoa soon became fashionable in Spain and Portugal.The Spanish were the first to add sugarto their cocoa drink.
http://www.123zcyy.com/shiti/59.html
By the middle of the century,solid chocolate was becoming familiar.In 1765,James Baker and John Hanan opened the first chocolate mill in the United States,introducing chocolate to the average citizen.In 1896,in Switzerland,Daniel Peter had the idea of adding milk in the chocolate-making process and produced the first milk chocolate.
Since then,chocolate has grown enormously in popularity.One of the biggest chocolate-eatingnations is Britain where the average man,women,and child eats nine kilos of chocolate a year.Infact,chocolate is the number one comfort food and there are more chocoholics in Britain than any where else in the world.Researchers warn that although chocolate is good for you,it should be eatenin small quantities and with no added milk. 41.Why is chocolate good for heaa and circulation? A.It reduces pain and stress.
B.It containS substances called flavonoids. C.It releases endorphins in human body. D.It acts like aspirin to protect heart.
42.When cocoa was first introduced to Europe_________,it soon became fashionable. A.as a drink B.as a gift C.as food D.as a medicine
43.What does James Bakers and John Hanan do about chocolate? A.They produce the first mild chocolate. B.They introduce chocolate to Europe. C.They add sugar to make chocolate bars. D.They make chocolate accessible to average man.
44.Which is the following statement is not true according to the passage? A.Chocolate contains substances that make people feel happy. B.Chocolate is good for health if it is eaten with added milk. C.Eating chocolate occasionally contributes to a healthy diet. D.Chocolate is loved by millions of people worldwide. 45.What iS the author's tone about eating chocolates? A.ambiguous B.negative C.positive D.humorous
第5部分:补全短文(第46~50题,每题2分,共10分)