TEXT C
For millions of years before the appearance of the electric light， shift work，all-night cable TV and the Internet， Earth’s creatures evolved on a planet with predictable and reassuring 24－h(huán)our rhythms. Our biological clocks are set for this daily cycle.Simply put，our bodies want to sleep at night and be awake during the day. Most women and men need between eight and eight and a half hours of sleep a night to function properly throughout their lives.(Contrary to popular belief，humans don’t need less sleep as they age.)
But on average，Americans sleep only about seven and a half hours per night，a marked drop from the nine hours day averaged in 1910.what’s worse，nearly one third of all Americans get less than six hours of sleep on a typical work night. For most people， that’s not nearly enough.
Finding ways to get more and better sleep can be a challenge. Scientists have identified more than 80 different sleep disorders. Some sleeping disorders are generic. But many problems are caused by staying up late and sleeping in， by traveling frequently between time zones or by working nights. Dr. James. F. Jones at National Jewish Medical and Research Center in Denver says that sleep disorders are often diagnosed at other discomforts. About one third of the patients referred to him with possible chronic fatigue syndrome actually have treatable sleep disorders. “Before we do anything else， we look at their sleep，” Jones says.
Sleep experts say that most people would benefit from a good look at their sleep patterns， “My motto (座右銘) is ‘sleep defensively’，” says Mary Carskadon of Brown University. She says people need to carve out sufficient time to sleep， even if it means giving up other things. Sleep routines－like going to bed and getting up at the same time every day－are important. Pre－bedtime activities also make a difference. As with Elsneer， who used to suffer from sleeplessness， a few lifestyle change－avoiding stimulants and late meals， exercising hours before bedtime， relaxing with a hot bath—yield better sleep.
90.What is TRUE of human sleep？
A. Most people need less sleep when grow older.
B. Most people need seven and a half hours of sleep every night.
C. On average， people in the U. S. today sleep less per night than they used to.
D. For most people， less than six hours of sleep on a typical work night is enough.
91.For our bodies to function properly， we should .
A. sleep for at least eight hours per night
B. believe that we need less sleep as we age
C. adjust our activities to the new inventions
D. be able to predict the rhythms of our biological clocks
92.According to the author， many sleeping disorders are caused by .
A. other diseases
B. pre－bedtime exercises
C. improper sleep patterns
D. Chronic fatigue syndrome
93.Which of the following measures can help you sleep better？
A. Staying up late.
B. Taking a hot bath.
C. Having late meals.
D. Traveling between time zones.
94.“Sleep defensively” means that .
A. people should go to a doctor and have their problems diagnosed
B. people should exercise immediately before going to bed every night
C. people should sacrifice other things to get enough sleep if necessary.
D. People should give up going to bed and going up at the same every day.
TEXT D
The word laser was coined as an acronym for Light Amplification by the Stimulated Emission of Radiation. Ordinary light， from the Sun or a light bulb， is emitted spontaneously， when atoms or molecules get rid of excess energy by themselves， without any outside intervention. Stimulated emission is different because it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light.
Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However， for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought ways by which one atom or molecule could stimulate many others to emit light， amplifying it to much higher powers.
The first to succeed was Charles H. Townes， then at Columbia University in New York. Instead of working with light， however， he worked with microwaves， which have a much longer wavelength， and built a device he called a “maser”， for Microwave Amplification by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951， the first maser was not completed until a couple of years later. Before long， many other physicists were building masers and trying to discover how to produce stimulated mission at even shorter wavelengths.
The key concepts emerged about 1957. Townes and Arthur Schawlow， then at Bell Telephone Laboratories， wrote a long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time， similar ideas crystallized in the mind of Gordon Gould， then a 37-year-old graduate student at Columbia， who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal， Physical Review Letters， but Gould filed a patent application. Some decades later， people still argue about who deserves the credit for the concept of the laser.
95.Which of the following statements best describes a laser？
A.A device for stimulating atoms and molecules to emit light.
B.An atom in a high-energy state.
C.A technique for destroying atoms or molecules.
D.An instrument for measuring light waves.
96.Why was Townes' early work with stimulated emission done with microwaves？
A.He was not concerned with light amplification.
B.It was easier to work with longer wavelengths.
C.His partner Schawlow had already begun work on the laser.
D.The laser had already been developed.
97.In his research at Columbia University， Charles Townes worked with all of the following EXCEPT .
A.stimulated emission B.microwaves C.light amplification D.a maser
98.In approximately what year was the first maser built？
A.1917. B.1951. C.1953. D.1957.
99.Why do people still argue about who deserves the credit for the concept of the laser？
A. The researchers' notebooks were lost.
B. Several people were developing the idea at the same time.
C .No one claimed credit for the development until recently.
D. The work is still incomplete.
100.According to the passage，Townes，Arthur Schawlow，and Gordon Gould didn't .
A. come up with similar ideas about laser
B. write their ideas down
C. work at Columbia University
D. do their share for the study of the laser
TEXT E
You may not have thought of it just this way, but the letter you write is part of you, and expression of your personality. Therefore to write letters that are mere patterns of form is to present a colorless personality.
Letters, by their very nature, are too individual to be standardized. A letter may be absolutely perfect according to the standards of good taste and good form; but unless it also expresses something of the writer's personality, it is not a good letter.
In other words, don't be satisfied to write letters that are just correct and nothing more. Try to write letters that are correct for you... letters that are warm and alive with reflections of your own personality.
And if this sounds like a platitude (陳詞濫調(diào)), stop for a moment and think back over your recent correspondence. What was the most interesting letter you received? Was it a letter anyone could have written? Or was it a letter that instantly “came alive” as you read it—that brought the personality of the sender right into the room with you. as though you were face to face, listening instead of reading?
The fault with too many letters, today as in the past—the reason so many letters are dull and lifeless, and often fail to accomplish the purpose for which they are written is simply this: They sound exactly like the letters everyone else writes. They are neither exciting to receive nor stimulating to read.
98. What does the author mean by saying “the letter you write is part of you”?
A. Writing letters plays an important part in your life.
B. When you write letters, you should be careful about what to write.
C. People can see your personality from the letters you write.
D. You should write good letters.
99. What does the author want to explain in the fourth paragraph?
A. A good letter presents one's personality.
B. His opinion is a platitude.
C. Letter-writing is interesting.
D. Talking face to face is a better way to communicate than writing letters.
100. The best title for the passage is___________.
A. Letter Writing B. Personality in Letter Writing
C. To Write Interesting Letters D. To Write Correct Letters
For millions of years before the appearance of the electric light， shift work，all-night cable TV and the Internet， Earth’s creatures evolved on a planet with predictable and reassuring 24－h(huán)our rhythms. Our biological clocks are set for this daily cycle.Simply put，our bodies want to sleep at night and be awake during the day. Most women and men need between eight and eight and a half hours of sleep a night to function properly throughout their lives.(Contrary to popular belief，humans don’t need less sleep as they age.)
But on average，Americans sleep only about seven and a half hours per night，a marked drop from the nine hours day averaged in 1910.what’s worse，nearly one third of all Americans get less than six hours of sleep on a typical work night. For most people， that’s not nearly enough.
Finding ways to get more and better sleep can be a challenge. Scientists have identified more than 80 different sleep disorders. Some sleeping disorders are generic. But many problems are caused by staying up late and sleeping in， by traveling frequently between time zones or by working nights. Dr. James. F. Jones at National Jewish Medical and Research Center in Denver says that sleep disorders are often diagnosed at other discomforts. About one third of the patients referred to him with possible chronic fatigue syndrome actually have treatable sleep disorders. “Before we do anything else， we look at their sleep，” Jones says.
Sleep experts say that most people would benefit from a good look at their sleep patterns， “My motto (座右銘) is ‘sleep defensively’，” says Mary Carskadon of Brown University. She says people need to carve out sufficient time to sleep， even if it means giving up other things. Sleep routines－like going to bed and getting up at the same time every day－are important. Pre－bedtime activities also make a difference. As with Elsneer， who used to suffer from sleeplessness， a few lifestyle change－avoiding stimulants and late meals， exercising hours before bedtime， relaxing with a hot bath—yield better sleep.
90.What is TRUE of human sleep？
A. Most people need less sleep when grow older.
B. Most people need seven and a half hours of sleep every night.
C. On average， people in the U. S. today sleep less per night than they used to.
D. For most people， less than six hours of sleep on a typical work night is enough.
91.For our bodies to function properly， we should .
A. sleep for at least eight hours per night
B. believe that we need less sleep as we age
C. adjust our activities to the new inventions
D. be able to predict the rhythms of our biological clocks
92.According to the author， many sleeping disorders are caused by .
A. other diseases
B. pre－bedtime exercises
C. improper sleep patterns
D. Chronic fatigue syndrome
93.Which of the following measures can help you sleep better？
A. Staying up late.
B. Taking a hot bath.
C. Having late meals.
D. Traveling between time zones.
94.“Sleep defensively” means that .
A. people should go to a doctor and have their problems diagnosed
B. people should exercise immediately before going to bed every night
C. people should sacrifice other things to get enough sleep if necessary.
D. People should give up going to bed and going up at the same every day.
TEXT D
The word laser was coined as an acronym for Light Amplification by the Stimulated Emission of Radiation. Ordinary light， from the Sun or a light bulb， is emitted spontaneously， when atoms or molecules get rid of excess energy by themselves， without any outside intervention. Stimulated emission is different because it occurs when an atom or molecule holding onto excess energy has been stimulated to emit it as light.
Albert Einstein was the first to suggest the existence of stimulated emission in a paper published in 1917. However， for many years physicists thought that atoms and molecules always were much more likely to emit light spontaneously and that stimulated emission thus always would be much weaker. It was not until after the Second World War that physicists began trying to make stimulated emission dominate. They sought ways by which one atom or molecule could stimulate many others to emit light， amplifying it to much higher powers.
The first to succeed was Charles H. Townes， then at Columbia University in New York. Instead of working with light， however， he worked with microwaves， which have a much longer wavelength， and built a device he called a “maser”， for Microwave Amplification by the Stimulated Emission of Radiation. Although he thought of the key idea in 1951， the first maser was not completed until a couple of years later. Before long， many other physicists were building masers and trying to discover how to produce stimulated mission at even shorter wavelengths.
The key concepts emerged about 1957. Townes and Arthur Schawlow， then at Bell Telephone Laboratories， wrote a long paper outlining the conditions needed to amplify stimulated emission of visible light waves. At about the same time， similar ideas crystallized in the mind of Gordon Gould， then a 37-year-old graduate student at Columbia， who wrote them down in a series of notebooks. Townes and Schawlow published their ideas in a scientific journal， Physical Review Letters， but Gould filed a patent application. Some decades later， people still argue about who deserves the credit for the concept of the laser.
95.Which of the following statements best describes a laser？
A.A device for stimulating atoms and molecules to emit light.
B.An atom in a high-energy state.
C.A technique for destroying atoms or molecules.
D.An instrument for measuring light waves.
96.Why was Townes' early work with stimulated emission done with microwaves？
A.He was not concerned with light amplification.
B.It was easier to work with longer wavelengths.
C.His partner Schawlow had already begun work on the laser.
D.The laser had already been developed.
97.In his research at Columbia University， Charles Townes worked with all of the following EXCEPT .
A.stimulated emission B.microwaves C.light amplification D.a maser
98.In approximately what year was the first maser built？
A.1917. B.1951. C.1953. D.1957.
99.Why do people still argue about who deserves the credit for the concept of the laser？
A. The researchers' notebooks were lost.
B. Several people were developing the idea at the same time.
C .No one claimed credit for the development until recently.
D. The work is still incomplete.
100.According to the passage，Townes，Arthur Schawlow，and Gordon Gould didn't .
A. come up with similar ideas about laser
B. write their ideas down
C. work at Columbia University
D. do their share for the study of the laser
TEXT E
You may not have thought of it just this way, but the letter you write is part of you, and expression of your personality. Therefore to write letters that are mere patterns of form is to present a colorless personality.
Letters, by their very nature, are too individual to be standardized. A letter may be absolutely perfect according to the standards of good taste and good form; but unless it also expresses something of the writer's personality, it is not a good letter.
In other words, don't be satisfied to write letters that are just correct and nothing more. Try to write letters that are correct for you... letters that are warm and alive with reflections of your own personality.
And if this sounds like a platitude (陳詞濫調(diào)), stop for a moment and think back over your recent correspondence. What was the most interesting letter you received? Was it a letter anyone could have written? Or was it a letter that instantly “came alive” as you read it—that brought the personality of the sender right into the room with you. as though you were face to face, listening instead of reading?
The fault with too many letters, today as in the past—the reason so many letters are dull and lifeless, and often fail to accomplish the purpose for which they are written is simply this: They sound exactly like the letters everyone else writes. They are neither exciting to receive nor stimulating to read.
98. What does the author mean by saying “the letter you write is part of you”?
A. Writing letters plays an important part in your life.
B. When you write letters, you should be careful about what to write.
C. People can see your personality from the letters you write.
D. You should write good letters.
99. What does the author want to explain in the fourth paragraph?
A. A good letter presents one's personality.
B. His opinion is a platitude.
C. Letter-writing is interesting.
D. Talking face to face is a better way to communicate than writing letters.
100. The best title for the passage is___________.
A. Letter Writing B. Personality in Letter Writing
C. To Write Interesting Letters D. To Write Correct Letters