Like distance runners on a measured course, all of us will move through time in a roughly predictable
pattern.
In the first stage of our lives, we develop and grow, reaching toward the top of physical
vitality(energy).
After we grow up,however, the body begins a process of gradually wearing out.
A new awareness of physical fitness may help lengthen our years of health and vitality, yet nothing we
do will work to stop the unavoidable force of aging.
Most of the changes of aging take place deep inside the body. The lungs become less able to take in
oxygen. Powerful muscles gradually lose their strength. The heart loses power and pumps less blood.Bones grow easier to break.
Finally, we meet a stress,a stress that is greater than our physical resistance. Often it is only a minor
accident or chance infection(a disease eaused by virus), but this time,it brings life to an end.
In 1932, a classic experiment nearly doubled the lifetime of rats, simply by cutting back the
calories(unit for measuring the energy value of food)in their diet.The reason for the effect was then
unknown.
Today, at the university of California at Berkley, Dr.Paul Seagle has also greatly lengthened the
normal lifetime of rats. The result was achieved through a special protein(蛋白质)limited diet, which
had a great effect on the chemistry of the brain. Seagle showed that within the brain, specific chemicals
control many of the signals that influence aging. By changing that chemical balance, the clock of aging
can be reset.
For the first time, the mystery(something that is difficult to understand or to explain)of why our age
is being seriously challenged. Scientists in many fields are now making striking and farreaching
discoveries.
An average lifetime lasts 75 years, yet in each of us lies a potential for a longer life. If we could keep
the vitality and resistance to disease that we have at age twenty, we would live for 80 years.
1. What does the underlined word"it" refer to?
A. Physical vitality.
B. Stress.
C. Aging.
D. Physical resistance.
2. The author believes the following EXCEPT that ________.
A. human"s life pattern is predictable
B. physical fitness can"t stop the force of aging
C. human"s lifetime will last longer than 75 years
D. all of the changes of aging take place deep inside the body
3. How did Dr.Paul Seagle lengthen the lifetime of rats in his experiment?
A. By limiting the protein in their diet.
B. By cutting the calories in their diet.
C. By resetting their clock of aging.
D. By keeping their physical fitness.
4. What is probably the best title for the article?
A. Two Great Experiments
B. The Mystery of Human Life
C. Ways to Lengthen Human Life
D. The Breakthrough in the Study of Aging
Lake Ontario.Surprisingly,the 22gun ship is wellpreserved in the cold,deep water.Explorers
announced the news recently.
Kennard is an electrical engineer.He has been diving for nearly 40 years and has found more
than 200 wrecks(残骸) in the Great Lakes and other lakes or rivers.He began searching the
Ontario 35 years ago but quit after several dives.Six years ago,he began to work with Scoville,a
diver.Since then,the pair have found seven ships in the lake.Over the years,Kennard got licenses
and information,including the ship"s design plans,from the British government.Even then,it took the
pair three years to search more than 200 square miles before they found the ship earlier this month.
After locating the wreck with the sonal(声纳),the explorers used a submarine to confirm their
find.The 80foot ship is the only entire British ship ever found in the Great Lakes,Scoville and
Kennard said."To have a ship from the Revolutionary War that"s nearly entire is unbelievable.It"s
an archaeological miracle."They said the ship is still considered the property of the British Admiralty.
Although the ship sits in an area where the water is up to 500 feet deep and cannot be reached by
anyone but the most experienced divers,Kennard and Scoville refused to give its exact location with
care.They only said that it was found off the southern shore.
The ship was discovered resting partially on its side.It went down on October 31,1780,with 60
British soldiers, a crew of about 40,mostly Canadians,and possibly about 30 American war prisoners.
The explorers also found two cannons and the ship"s bell.
B.has kept searching the Ontario for 35 years
C.is both an engineer and an experienced diver
D.got to know Scoville when he was very young
B.needed a lot of experts"s support
C.was forbidden by the government
D.was made completely by accident
B.will become world famous because of their find
C.may not have succeeded without modern technology
D.will be given a large reward by the American government
B.they were afraid that something unexpected might happen
C.they wanted to keep it a secret forever
D.they thought it would be interesting for people to guess where it is
nations.They say people should eat more of the same kind of food eaten by humans living more than
10,000 years ago.__1__
The scientists say that the human life has changed greatly.Our bodies have not been able to deal
with these changes in lifestyle and this had led to new kinds of sicknesses.__2__ So they are called
"diseases of civilization".Many cancers and diseases of the blood system are examples of such
diseases.
Scientists noted that people in both the Old Stone Age and the New Stone Age enjoyed very little
alcohol or tobacco,probably none.__3__ However,a change in food is one of the main differences
between life in ancient times and that of today.
Stone Age people hunted wild animals for their meat,which had much less fat than domestic ones.
They ate a lot of fresh wild vegetables and fruits.They did not have milk or any other dairy products,
and they made very little use of grains.__4__ We eat six times more salt than our ancestors.We eat
more sugar.We eat twice as much fat but only one third as much protein and much less vitamin C.
__5__ But scientists say that we would be much healthier if we eat much the same way as our ancestors
did,cutting the amount of fatty,salty and sweet food.
A.These new sicknesses were not known in ancient times.
B.People today probably do not want to live the way people thousands of years ago did.
C.Ancient people also lived in large groups.
D.But today,we eat a lot of these food.
E.Ancient people also got a great deal of physical exercise.
F.In that case,they would live much healthier.
G.People today probably live the same life as people thousands of years ago.
阅读理解。
Move Earth-it"s no science fiction
LONDON-Scientists have found an unusual way to prevent our planet from overheating:move it to
a cooler spot. All you have to do is send a few comets(彗星)in the direction of Earth, and its orbit will
be changed. Our world will then be sent spinning into a safer,c older part of the solar system.
This idea for improving our climate comes from a group of US National Aeronautics and Space
Administration (NASA) engineers and American astronomers. They say their plan could add another
six billion years to the useful lifetime of our planet-effectively doubling its working life.
The plan put forward by Dr. Laughlin, and his colleagues Don Korycansky and Fred Adams, needs
carefully directing a comet or asteroid so that it passes close by our planet and sends some of its
gravitational energy to Earth.
"Earth"s orbital speed would increase as a result and we would move to a higher orbit away from
the Sun,"Laughlin said.
Engineers would then direct their comet so that it passed close to Jupiter or Saturn. The comet
would pick up energy from one of these giant planets. Later its orbit would bring it back to Earth, and
the process would be repeated.
In the short term, the plan provides an ideal way to global warming,although the team was actually
concerned with a much greater danger. The sun is certain to heat up in about a billion years and so
"seriously compromise" our biosphere(生物圈)-by cooking us.
That" s why the group decided to try to save Earth.
The plan has one or two worrying aspects, however. For a start,space engineers would have to
be very careful about how they directed their asteroid or comet towards Earth. The smallest
miscalculation(误算)in orbit could fire it straight at Earth-with deadly consequences.
There is also the question of the Moon. As the current issue of Scientific American magazine
points out, if Earth was pushed out of its current position it is "most likely the Moon would be
stripped away from Earth," it states. This would greatly change our planet" s climate.
1. What makes the scientists plan to move Earth?
A. A few comets are moving to the direction of Earth.
B. Earth" s working life is coming to an end soon.
C. Earth will become too hot for mankind to keep alive.
D. The moon is moving farther and farther away from Earth.
2. If the plan is successful,Earth will have a working life of________years.
A. 12 billion
B. 6 billion
C. 18 billion
D. 24 billion
3. What serious problems might the plan cause according to the passage?
A. The comet might hit Earth and man might lose the moon.
B. Earth might be moved too far away and man might be frozen to death.
C. The comet might hit Jupiter or Saturn and never return to Earth.
D. Earth" s working life might be greatly shortened.
4. What does the underlined word "compromise" mean?
A. provide
B. benefit
C. share
D. endanger
Although many Chinese students say that their knowledge of English grammar is good, most would
admit that their spoken English is poor. Whenever I speak to a Chinese student, they always say, "My
spoken English is poor." __1__ I would like to suggest that there may be some reasons for their
problems with spoken English.
First, they fail to find suitable words to express themselves due to a limited vocabulary. __2__
However, you can speak with a limited vocabulary, if you choose a positive attitude. Others will follow
you as long as you use the words that you know.
__3__Sometimes they make mistakes when they are speaking because they are shy and nervous.
Yet students should remember that their goal should be FLUENCY NOT ACCURACY. Your aim in
writing is to be accurate following the rules for grammar and using the right words and spelling them
correctly. However, in speaking your aim is fluency. You want to get your message across, to talk to
someone in English, as quickly and as well as you can, even though sometimes you may use a wrong
word or tense, but it doesn" t matter. __4__
The third reason is that not enough attention is paid to listening. You have one mouth but two ears!
All that hearing is necessary for you to start speaking.
Fourth, most Chinese students are reactive rather than proactive language learners. Instead of
actively seeking out opportunities to improve their spoken English they passively wait for speaking
opportunities to come to them and wonder why their English always remains poor. __5__
A. The person you are speaking to will understand you and make allowances for any mistakes he hears.
B. They may try to avoid making similar mistakes next time.
C. Obviously the better answer is to expand their vocabulary.
D. If you have this proactive outlook,then you will see English opportunities wherever you go.
E. However,their spoken English does not have to remain "poor"!
F. Second,they are afraid of making mistakes.
G. The second reason lies in the reluctance of using what has just been learned.
of days and night. Seasonal changes such as these are due to three factors, the tilt (倾斜) of Earth"s axis (轴) to one side; the rotation, or turn, of Earth on its axis every 24 hours; and the revolution of Earth
around the sun once every year. Since Earth remains titled in the same direction during its revolution of
the sun, our distance from the sun changes, causing us to experience the changing seasons.
In summer the Northern Hemisphere (半球), where we live, points toward the sun, bringing us closer
to it and its more direct and powerful rays. Six months later, when Earth is halfway through its revolution
around the sun, the Northern Hemisphere is tilted away from the sun, placing us farther from it and
exposing us to the weak rays of winter. The seasons in one hemisphere are opposite those in the other
hemisphere. However, one area of the Earth - the equator (赤道) - is always closest to the sun, so
equatorial regions experience hot weather throughout the year. In contrast, the polar regions, always
farthest from the sun, experience continuous frigid weather.
In the Northern Hemisphere, we observe a gradual alteration in the angle of the sun during the year.
About June 21, on the summer solstice, or the first day of summer, the midday sun reaches its highest
point in the sky and produces the year"s maximum daylight hours. About September 22, on the autumn
equinox, the midday sun is lower in the sky. Because Earth"s axis is titled neither toward nor away from
the sun, equal periods of daylight and darkness result. About December 21, on the winter solstice, or the
first day of winter, the midday sun is at its lowest point in the sky. This brings the year"s fewest daylight
hours. About March 21, on the vernal equinox, or the first day of spring, the midday sun is higher in the
sky. Daytime and nighttime hours are again equal.
1. This passage is mainly concerned with ____________.
A. how Earth rotates on its axis
B. why the various seasons occur
C. why each season is three months long
D. which parts of Earth are coldest
2. What happens on the summer solstice?
A. The midday sun reaches its lowest point in the sky.
B. Earth"s axis is tilted neither toward nor away from the sun.
C. There are equal periods of daylight and darkness.
D. The midday sun produces the greatest number of daylight hours during the year.
3. In the last paragraph, the writer presents facts about equinoxes and solstices to explain _________.
A. why it is hot at the equator
B. the various lengths of day and night
C. why the midday sun is directly overhead
D. the date of the autumn equinox
4. In this passage, the underlined word "revolution" in the first paragraph means ____________.
A. a great change
B. an uprising
C. standing still
D. circling
- 1我国地势西高东低,大致呈三级阶梯分布。读下图,回答相关问题。(1)写出图中字母代表的地形区名称: A
- 2曲线C:在处的切线方程为______.
- 3陈胡公妫满系舜帝之子商均的32世孙。公元前1046年,周武王灭商建周,把他封于陈,侯爵,并将长女太姬嫁给他。对此,以下解
- 4若实数x,y满足y≥1y≤2x-1x+y≤m,如果目标函数z=x-y的最小值为-2,则实数m=( )A.8B.0C.4
- 5只有在和平的国际环境中,世界各国才能保持正常的经济交往和顺利实现本国的发展计划。材料一:人民网报道:法国、英国和美国等国
- 6方程的解是 .
- 7On March 8th, Flight MH 370 went missing. The news brought g
- 8下列化常用语中,正确的是( )A.2个氮分子-2NB.氢氧化铁的化学式-Fe(OH)2C.H2O中氧元素的化合价为-2
- 9Could you please tell me ______ just now?[ ]A. what"s ha
- 10下图是探究影响酵母菌种群数量变化因素时获得的实验结果。有关分析错误的是[ ]A.O点时酵母菌的接种量会影响酵母菌
- 1张老师用2N的力沿水平方向推一辆在水平桌面上的小车,小车以较慢的速度沿力的方向做匀速直线运动,小车受到的摩擦力是____
- 2Do you wake up every morning ________ energetic and ready to
- 3如图为一小球从A点沿直线运动到F点的频闪照片,若频闪照相机每隔0.2s 闪拍一次,分析照片可知:小球从A点到F点作的是_
- 4多细胞生物体由小长大发育成熟的机理是A.细胞分裂→细胞生长→细胞分化B.细胞生长→细胞分裂→细胞分化C.细胞分化→细胞分
- 5下列对于逆反心理和逆反行为认识正确的是A.逆反行为是错误的,子女不应反抗父母B.逆反心理是正确的,子女应当反抗父母C.青
- 6若以x为未知数的方程3x-2a=0与2x+3a-13=0的根相同,则a= 。
- 7下列资源中,具有地带性分布特点的是 ( )A.水力资源B.森林资源C.煤炭资源D.铁矿资
- 8下列有关能源的说法正确的是[ ]A.氢能源没有污染并且成本低,现已普遍使用B.乙醇汽油既节约石油资源,又能促进农
- 9在与少数民族交往时,尊重少数民族的利益和习俗,就要 A.入乡随俗B.主随客便C.取长补短D.以我为主,为我所有
- 10气象卫星向地面发送的云图,是由卫星上的红外线感应器接收云层发出的红外线而形成的图象,云图上的黑白程度由云层的温度高低决定