Crown shyness(树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly visible from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.
There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.
In his 1955 book Growth Habits of the Eucalypts, Australian forester M.R. Jacobs writes that the growing tips of the trees are sensitive to abrasion(擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swinging in the wind and touching each other, they gradually fill up the gaps between them.
But while the above theory is arguably the most widespread, it’s certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. These pests have been known to work together and create structures that extend up to 10 cm off of tree branches in order to reach other plants, so the gaps are the trees’ natural defense method.
One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical element to stop other trees from growing too close.
Whatever the reason, one thing is for sure: plants are more intelligent than people used to think.
1.What can we know about crown shyness?
A. It can cause abrasion between trees.
B. It only happens between the same species.
C. It has been discovered for only half a century.
D. No agreement has been reached about its real cause.
2.What will happen if trees showing crown shyness are stopped from swinging?
A. The trees will stop growing and even die.
B. The gaps between the trees will grow wider.
C. The crown shyness phenomenon will disappear.
D. The gaps between the trees will remain the same.
3.What’s tree’s reaction when attacked by pests according to the text?
A. Swinging less in the wind
B. Leaving space between their crowns
C. Spreading their branches and leaves
D. Stopping growing for a period of time
4.Which statement might the Malaysian scholar agree with?
A. Trees have special ways to attack others.
B. Some insects stop trees growing too close.
C. Trees compete with their neighbors for light.
D. Trees won’t touch each other to avoid diseases.
高三英语阅读理解中等难度题
Crown shyness(树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly visible from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.
There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.
In his 1955 book Growth Habits of the Eucalypts, Australian forester M.R. Jacobs writes that the growing tips of the trees are sensitive to abrasion(擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swinging in the wind and touching each other, they gradually fill up the gaps between them.
But while the above theory is arguably the most widespread, it’s certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. These pests have been known to work together and create structures that extend up to 10 cm off of tree branches in order to reach other plants, so the gaps are the trees’ natural defense method.
One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical element to stop other trees from growing too close.
Whatever the reason, one thing is for sure: plants are more intelligent than people used to think.
1.What can we know about crown shyness?
A. It can cause abrasion between trees.
B. It only happens between the same species.
C. It has been discovered for only half a century.
D. No agreement has been reached about its real cause.
2.What will happen if trees showing crown shyness are stopped from swinging?
A. The trees will stop growing and even die.
B. The gaps between the trees will grow wider.
C. The crown shyness phenomenon will disappear.
D. The gaps between the trees will remain the same.
3.What’s tree’s reaction when attacked by pests according to the text?
A. Swinging less in the wind
B. Leaving space between their crowns
C. Spreading their branches and leaves
D. Stopping growing for a period of time
4.Which statement might the Malaysian scholar agree with?
A. Trees have special ways to attack others.
B. Some insects stop trees growing too close.
C. Trees compete with their neighbors for light.
D. Trees won’t touch each other to avoid diseases.
高三英语阅读理解中等难度题查看答案及解析
It is one of the greatest mysteries of nature. In case you haven’t noticed, all living things follow very definite, individual rhythms, all as regular as a clock, but what makes them regular?
Though many scientists maintain that these rhythms are the result of some outside force like gravity or radiation or both, the results of most scientific researches agree with other scientists who believe that each living thing has its own built-in biological “time clock.”
Take the mystery of migration for example. Scientists can’t really explain why many species of birds migrate in the autumn even though the temperature is still summery. The birds just seem to snub the comfortable weather that they are having. When a certain time comes, they travel south by the thousand. In spring time, they migrate northwards even though there probably is snow still covering the ground when they finally arrive. Something said “go,” and they did.
Animals that hibernate (冬眠) are obeying individual time clocks, too. When their clock indicates the time to take a winter’s nap, they do, and nothing can stop them. At a certain time in the spring, they wake up and come out regardless of the weather outside.
Plants appear to have yearly rhythms, such as the sprouting of seeds, and they also have daily rhythms. Notice sometimes that plants raise their leaves in daylight and lower them at night.
If you live along the California coast, you can easily observe a demonstration of this mysterious clock functioning regularly. There, from February to September, the highest tides occur exactly every fourteen and four-fifths days, and during these high tides, but at no other time, small silvery fish called grunions surf-ride a wave to the beach. There the female deposits her eggs in the sand and the male fertilizes them; then both hitch a wave-ride back to the sea. Exactly fourteen and four-fifths days later, never before or after, the tiny eggs hatch, and the high tide carries the new babies out to sea.
72. According to the passage, the mysterious rhythms result from ______.
A. the influence of gravity on living species
B. the effect of radiation on living species
C. the influence of a mysterious outer force on living species
D. the internal mechanism inside the living species
73. The underlined word “snub” in the third paragraph probably means ______.
A. fight B. ignore C. symbolize D. criticize
74. Which of the following statements is NOT TRUE?
A. Hibernating animals are obeying an internal time clock.
B. The positioning of the leaves of some plants is due to the daily rhythms.
C. The internal clock functioning is demonstrated in the reproducing habits of grunions.
D. The yearly hibernation is more because of the weather influence than the biological functioning.
75. The passage is mainly about ______.
A. the rhythms of life
B. the reasons of mysterious hibernation
C. strange behaviors of species
D. the timing for different events in the world of species
高三英语阅读理解简单题查看答案及解析
—It is a mystery and a shock to all who knew him that he____ have taken his own life in this way.
—What a pity, indeed.
A. must B. may
C. can D. should
高三英语单项填空中等难度题查看答案及解析
—It is a mystery and a shock to all who knew him that he____ have taken his own life in this way.
—What a pity, indeed.
A. must B. may
C. can D. should
高三英语单项填空简单题查看答案及解析
What is most significant is the way ______ people have worked in harmony with nature.
A.which B.in which C.for which D.on which
高三英语单项填空简单题查看答案及解析
I wonder _______ there are so many natural disasters across the world in 2010.
A．why is it B．it is why that C．why is it that D．why it is that
高三英语单项填空简单题查看答案及解析
I wonder _______ there are so many natural disasters across the world in 2010.
A．why is it B．it is why that C．why is it that D．why it is that
高三英语单项填空困难题查看答案及解析
I wonder _______ there are so many natural disasters across the world in 2010.
A．why is it B．it is why that C．why is it that D．why it is that
高三英语单项填空中等难度题查看答案及解析
Competition is a common phenomenon in our social life. 1. There is constant competition for academic degrees, jobs, customers, money and so forth. In a sense, competition is one of the motive forces to the development of society.
2. Therefore, the only way to survive is to be competitive. Growing in a competitive environment is important for a child because future adult life is difficult. Finding a good job, for example, is an extremely competitive activity.
Today, most people obtain knowledge through various ways and a large number of people get good education. 3.The quality of people is rapidly increasing. Competition is more violent than what we thought it should be. The potentially successful job applicant has to be prepared in stronger position by gaining more qualifications and experience. In the sports contests, the strongest will come out as winners. In the business world, to beat your competitors, you must be better than the other employees. 4.
Though the only way our world rewards people is to give honor to the winners, not to the losers, by attempting to compete at different activities, we can still learn to win and lose, gain experience and know our strengths and weaknesses. Competition prepares us for the tough things in life.
Whether in games, in study or in business alike, the aim is to win the game, the degree, the trophy, and the contract. 5.
A. Otherwise, you will be defeated.
B. Modern society demands high-quality talents.
C. Learning to be competitive is clearly the best preparation for life.
D. There are also many people who have higher degrees in their special fields.
E. Children have to learn to be competitive in order to adapt to modern society.
F. In the natural world, the weak will be replaced by the strong and the fittest can live.
G. We compete when we play games and when we try to do better than others in our study.
高三英语七选五困难题查看答案及解析
Competition is a common phenomenon in our social life.1.There is constant competition for academic degrees, jobs, customers, money and so forth. In a sense, competition is one of the motive forces to the development of society.
2.Therefore, the only way to survive is to be competitive. Growing in a competitive environment is important for a child because future adult life is difficult. Finding a good job, for example, is an extremely competitive activity.
Today, most people try to get good education through various ways.3.The quality of people is rapidly increasing. Competition is more violent than what we thought it should be. The potentially successful job applicant has to be prepared in stronger position by gaining more qualifications and experience. In the business world, to beat your competitors, you must be better than the other employees.4.
In fact, the only way our world rewards people is to give honor to the winners, not to the losers. By attempting to compete at different activities, we learn to win and lose, gain experience and know our strengths and weaknesses. Competition prepares us for the tough things in life.5.
A.Otherwise, you will be defeated.
B.Modern society demands high-quality talents.
C.Learning to be competitive is clearly the best preparation for the tough life.
D.There are also many people who have higher degrees in their special fields.
E.Children have to learn to be competitive in order to adapt to modern society.
F.In the natural world, the weak will be replaced by the strong and the fittest can live.
G.We compete when we play games and when we try to do better than others in our study.
高三英语七选五中等难度题查看答案及解析