Big trees are very important in ecology. For ...

Big trees are very important in ecology. For a start, they provide food for countless other species and shelter for many animals. With their tall branches in the sun, they take in vast amounts of energy. This allows them to produce massive crops of fruit and flowers that much of the animal life in the forest feed on.

Only a small number of tree species have the genetic(基因的) ability to grow really big. The biggest are native to North America, but big trees grow all over the globe, from the tropics(热带地区) to the forests of the high latitudes(纬度). To achieve giant size, a tree needs three things: the right place to establish(建立) its seedling, good growing conditions and lots of time with low adult death rate. Lose any of these, and you will lose your biggest trees.

In some parts of the world, populations of big trees are dwindling because their seedlings cannot survive. In southern India, for instance, an aggressive non-native bush, Lantana camara, is invading the floor of many forests. Lantana grows so thickly that young trees often fail to take root. With no young trees to replace them, it is only a matter of time before most of the big trees disappear.

Without the right growing conditions, trees cannot get really big and there is some evidence to suggest tree growth could slow in a warmer world, particularly in environments that are already warm. Having worked for decades at La Selva Biological Station in Puerto Viejo de Sarapiqui, Costa Rica, David and Deborah Clark and colleagues have shown that tree growth there slows obviously in warmer years. “During the day, their growth shuts down when it gets too warm, and at night they consume more energy because their metabolic(新陈代谢的) rate increases,” explains David Clark. With less energy produced in warmer years and more being consumed just to survive, there is even less energy available for growth.

The Clarks’ theory, if correct, means tropical forests would be smaller over time. The largest, oldest trees would gradually die off and tend not to be replaced. According to the Clarks, this might cause a destabilization of the climate; as older trees die, forests would release some of their stored carbon into the atmosphere, causing a cycle of further warming, forest shrinkage and carbon emissions.

Besides, big trees face threats from elsewhere.

1.According to the passage, big trees make great contributions to the ecosystem because ________.

A. they can take in large amounts of energy

B. they determine the change of global climate

C. they provide the essentials for many creatures

D. they can improve a new cycle of further warming

2.All the following factors are a must for making big trees EXCEPT ______.

A. no deadly damage

B. the suitable place for new plants’ growing

C. good environment for growth

D. the highest location

3.The word “dwindling” (paragraph3) is closest in meaning to “______”.

A. exploding　　　　 B. growing

C. changing　　　　 D. dropping

4.What is the best title of the passage?

A. Big trees in trouble.

B. Advantages of big trees.

C. Results of big trees’ disappearing.

D. Importance of big trees to humans.

5.What will the author most probably discuss after the last paragraph?

A. More threats to the existence of big trees.

B. The effect of human activities on big trees.

C. Benefits of big trees to the whole atmosphere.

D. Comparison between common trees and big ones.

高二英语阅读理解中等难度题查看答案及解析

Big trees are incredibly important ecologically. For a start, they provide food for countless other species and shelter for many animals. With their tall branches in the sun, they capture vast amounts of energy. This allows them to produce massive crops of fruit and flowers that sustain much of the animal life in the forest.

Only a small number of tree species have the genetic ability to grow really big. The biggest are native to North America, but big trees grow all over the globe, from the tropics to the forests of the high latitudes (纬度). To achieve giant size, a tree needs three things: the right place to establish its seedling, good growing conditions and lots of time with low adult death rate. Lose any of these, and you will lose your biggest trees.

In some parts of the world, populations of big trees are dwindling(逐渐变少) because their seedlings cannot survive. In southern India, for instance, an aggressive non-native bush, Lantana camara, is invading the floor of many forests. Lantana grows so thickly that young trees often fail to take root. With no young trees to replace them, it is only a matter of time before most of the big trees disappear.

Without the right growing conditions, trees cannot get really big and there is some evidence to suggest tree growth could slow in a warmer world, particularly in environments that are already warm. Having worked for decades at La Selva Biological Station in Puerto Viejo de Sarapiqui, Costa Rica, David and Deborah Clark and colleagues have shown that tree growth there declines markedly in warmer years. “During the day, their growth shuts down when it gets too warm, and at night they consume more energy because their metabolic (新陈代谢) rate increases,” explains David Clark. With less energy produced in warmer years and more being consumed just to survive, there is even less energy available for growth.

The Clarks’ theory, if correct, means tropical forests would shrink over time. The largest, oldest trees would progressively die off and tend not to be replaced. According to the Clarks, this might cause a destabilization(不稳定) of the climate; as older trees die, forests would release some of their stored carbon into the atmosphere, causing a cycle of further warming, forest shrinkage and carbon emissions.

Besides, big trees face threats from elsewhere.

1.According to the passage, big trees make great contributions to the ecosystem　 because 　　　　　 .

A. they can capture large amounts of energy.

B. they determine the change of global climate.

C. they provide the essentials for many creatures.

D. they can avoid a new cycle of further warming.

2.All the following factors are a must for making big trees EXCEPT 　　　　　 .

A. no deadly damage B. genetic contribution

C. ideal environment for growth D. high-latitude location

3.What is the best title of the passage?

A. Big trees in trouble. B. Advantages of big trees.

C. Results of big trees’ disappearing. D. Importance of big trees to humans.

4.What will the author most probably discuss after the last paragraph?

A. More threats to the existence of big trees.

B. The effect of human activities on big trees.

C. Benefits of big trees to the whole atmosphere.

D. Comparison between common trees and big ones.

高二英语阅读理解中等难度题查看答案及解析

阅读下列短文，从每题所给的四个选项(A、B、C和D)中,选出最佳选项。

Big trees are incredibly important ecologically. For a start, they provide food for countless other species and shelter for many animals. With their tall branches in the sun, they capture vast amounts of energy. This allows them to produce massive crops of fruit and flowers that sustain much of the animal life in the forest.

Only a small number of tree species have the genetic ability to grow really big. The biggest are native to North America, but big trees grow all over the globe, from the tropics to the forests of the high latitudes(纬度). To achieve giant size, a tree needs three things: the right place to establish its seeding, good growing conditions and lots of time with low adult death rate. Lose any of these, and you will lose your biggest trees.

In some parts of the world, populations of big trees are dwindling because their seedings cannot survive. In southern India, for instance, an aggressive non-native bush, Lantana camara, is invading the floor of many forests. Lantana grows so thickly that young trees often fail to take root. With no young trees to replace them, it is only a matter of time before most of the big trees disappear.

Without the right growing conditions, trees cannot get really big and there is some evidence to suggest tree growth could slow in a warmer world, particularly in environments that are already warm. Having worked for decades at La Selva Biological Station in Puerto Viejo de Sarapiqui, Costa Rica, David and Deborah Clark and colleagues have shown that tree growth there declines markedly in warmer years. “During the day, their growth shuts down when it gets too warm, and at night they consume more energy because their metabolic(新陈代谢的)rate increases,” explains David Clark. With less energy produced in warmer years and more being consumed just to survive, there is even less energy available for growth.

The Clarks’ theory, if correct, means tropical forests would shrink over time. The largest, oldest trees would progressively die off and tend not to be replaced. According to the Clarks, this might cause a destabilization of the climate; as older trees die, forests would release some of their stored carbon into the atmosphere, causing a cycle of further warming, forest shrinkage and carbon emissions.

Besides, big trees face threats from elsewhere.

1. All the following factors are a must for making big trees EXCEPT_________.

A. genetic contribution

B. no deadly damage

C. ideal environment for growth

D. right place to establish its seeding

2.The word “dwindling”(paragraph3) is closest in meaning to “_______”.

A. exploding　　　　　 B. decreasing

C. changing　　　　　　 D. growing

3. What is the best title of the passage?

A. Results of big trees’ disappearing.

B. Advantage of big trees.

C. Big trees in trouble

D. Importance of big trees to humans.

4.What will the author most probably discuss after the last paragraph?

A. Comparison between common trees and big ones.

B. The effect of human activities on big trees.

C. Benefits of big trees to the whole atmosphere.

D. More threats to the existence of big trees.

高二英语阅读理解中等难度题查看答案及解析

We　 can’t deny that trees are useful to man in three very important ways: they provide him with wood and other products, they give him shade, and they help to prevent drought and floods.

Unfortunately, in many parts of the world man has not realized that the third of these services is the most important. In his eagerness to draw quick profit from the trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had.

Two thousand years ago a rich and powerful country cut down its trees to build warships, with which to gain itself an empire. It gained the empire but, without its trees, its soil became hard and poor. When the empire fell to pieces, the country found itself faced by floods and starvation.

Even though a government realizes the importance of a plentiful supply of trees, it is difficult for it to persuade the villager to see this. The villager wants wood to cook his food, and he can earn money by making charcoal or selling wood to the townsman. He is usually too lazy or too careless to plant and look after trees. So unless the government has a good system of control, or can educate the people, the forests will slowly disappear.

This does not only mean that the villagers’ sons and grandsons have fewer trees. The results are even more serious. For where there are trees ,their roots break the soil up, allowing the rain to sink in and also bind the soil, thus preventing it being washed away easily, but where there are no trees, the soil becomes hard and poor. The rain falls on hard ground and flows away on the surface, causing floods and carrying away the rich topsoil, in which crops grow so well. When all the topsoil is gone, nothing remains but worthless desert.

1.It’s a great pity that ________.

A. man is only interested in building empires

B. man is eager to profit from trees

C. man hasn’t realized the importance of trees to him

D. man hasn’t found out that he has lost all trees

2.Sooner or later the forests will disappear______

A. unless people are taught the importance of planting trees

B. unless people stop cutting down their trees

C. unless a county has a plenty supply of trees

D. unless the government punishes those who cut trees instead of planting trees

3.The word “bind” in Paragraph 5 means”_________”

A. to make stay together　　　　　 　 B.　 to make wet

C. to wash away　　　　　　　　　　　　 D.　 to improve

4.When there is a heavy rain ,trees can help to prevent floods, as they can ___________

A. keep rain from falling down to soft ground

B. cause the soil to allow rainwater to sink in

C. prevent the soil from being washed away

D. make the topsoil stick together

高二英语阅读理解中等难度题查看答案及解析

It is very important for people to drink water in our everyday life. Many people believe they are supposed to drink eight glasses of water a day, or about two liters. Why? Because that is what they have been told all their life. But a recent report offers some different advice. Experts say people should obey their bodies; they should drink as much water as they feel like drinking. The report says most healthy people meet their daily needs for liquid by letting thirst be their guide. The report is from the Institute of Medicine, part of the National Academies. The report contains some general suggestions. The experts say women should get about 2.7 liters of water daily. Men should get about 3.7 liters. But wait——in each case, that is more than eight glasses.

There is one important difference. The report does not tell people how many glasses of water to drink. In fact, the experts say it may be impossible to know how many glasses are needed to meet these guidelines. This is because the daily water requirement can include the water content in foods. People do not get water only by forcing themselves to drink a set number of glasses per day. People also drink fruit juices and sodas and milk. They drink coffee and tea. These all contain water. Yet some also contain caffeine. This causes the body to expel(排出)more water. But the writers of the report say this does not mean the body loses too much water.

As you might expect, the Institute of Medicine says people need to drink more water when they are physically active. The same is true of those who live in hot climates. Depending on heat and activity, people could need two times as much water as others do. All this, however, does not answer one question. No one seems sure why people have the idea that good health requires eight glasses of water daily.

It may have started with a misunderstanding. In 1945, the National Academy of Sciences published some guidelines. Its Food and Nutrition Board(营养膳食) said a good amount of water for most adults was 2.5 liters daily. This was based on an average of one milliliter(毫升)for each calorie of food eaten. But that was only part of what the board said. It also said that most of this amount is contained in prepared foods.

1.In experts’ opinion, every day a person should drink ____.

A. as much water as he can                 B. more than eight glasses of water

C. according to actual need for his body           D. when he comes in sight of water

2.What is mainly described in the second paragraph?

A. People know about the daily water requirement.

B. People need water instead of all kinds of drink.

C. People get daily water not only from drinking.

D. People drink all kinds of drink every day.

3.Who might drink less water according to the third paragraph?

4.The main purpose of writing the texts is to _______.

A. make a good suggestion of drinking daily  B. make clear the requirements to drink daily

C. tell the importance of drinking water daily     D. figure out a good amount of water daily

高二英语阅读理解中等难度题查看答案及解析

Trees are useful to man in three important ways: They provide him with wood and other products; they provide him shade;. and they help to prevent droughts（早灾）and floods.

Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important．In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.

This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind（固定）the soil, thus preventing it from being washed away easily；but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.

Two thousand years ago，a rich and powerful country cut down its trees to build warships, with which to gain itself an empire(帝国）．It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation（饥荒）．

1.The most important service of trees to man is that___________．

A. they give them wood and other products      B. they give them shade

C. they help him prevent droughts and floods    D. they help him made money

2.In many parts of the world, forests slowly disappear because___________．

A. many trees have been cut down by man    B. man has not paid enough attention to planting trees

C. new trees are not looked after properly     D. all the above

3.Land becomes desert after all trees are cut down because____________．

A. roots of trees break up the soil              B. there are too many rainfalls

C. there are no larger trees to keep rain and protect the top-soil   D. strong winds bring a lot of sand

4.The country mentioned in the passage suffered from floods and starvation  because________.

A. it set up an empire             B. the empire fell to pieces

C. it built too many warships       D. it lost its trees

5.Which title best fits the passage?

A. Trees and Man               B. How Trees Prevent Droughts and Floods

C. How an Empire Fell          D. A Story about Trees.

高二英语阅读理解中等难度题查看答案及解析

For high school leavers starting out in the working world, it is very important to learn particular skills and practice how to behave in an interview or how to find all internship(实习). In some countries, schools have programs to help students onto the path to work. In the United States, however, such programs are still few and far between.

Research shows that if high schools provide career-related courses, students are likely to get higher earnings in later years. The students are more likely to stay in school, graduate and go on to higher education.

In Germany, students as young as 13 and 14 are expected to do internships. German companies work with schools to make sure that young people get the education they need for future employment.

But in America, education reform programs focus on how well students do in exams instead of bringing them into contact with the working world. Harvard Education school professor Robert Schwartz has criticized （批评）education reformers for trying to place all graduates directly on the four-year college track. Schwartz argued that this approach leaves the country’s most vulnerable(易受影响的)kids with no jobs and no skills.

Schwartz believed that the best career programs encourage kids to go for higher education while also teaching them valuable practical skills at high school. James Madison High School in New York, for example, encourages students to choose classes on career-based courses. The school then helps them gain on-the-job experience in those fields while they’re still at high school.

However, even for teens whose schools encourage them to connect with work, the job market is daunting. In the US, unemployment rates for 16-to 19-year-olds are above 20 percent for the third summer in a row. “The risk is that if teenagers miss out on the summer job experience, they become part of this generation of teens who had trouble in landing a job,” said Michael, a  researcher in the US.

1.What’s the main idea of the text?

A．The lack of career-based courses in US high schools.

B．Tips on finding jobs for high school leavers.

C．Arguments about recent US education reform.

D．Advice for American high school leavers.

2.According to Robert Schwartz, _________.

A．there is no need for kids to go for higher education in the US

B．students should get contact with the working world at high school

C．education reform should focus on students’ performance in exams

D．teenagers in the US can’t miss out on the summer job experience

3.The underlined word “daunting” in Paragraph 6 most probably means __________.

A．creative          B．interesting         C．discouraging       D．unbearable

4.What can be inferred from the text?

A．High school leavers with no practical skills can’t find a job at all.

B．Students with career-based courses never have problems finding a job.

C．US companies work with schools to prepare young people for future employment.

D．Unemployment rates for US teenagers remain high at the moment.

高二英语阅读理解中等难度题查看答案及解析

For high school leavers starting out in the working world，it is very important to learn particular skills and practice how to behave in an interview or how to find all internship(实习)．In some countries，schools have programs to help students onto the path to work．In the Unites States，however，such programs are still few and far between．

Research shows that if high schools provide career-related courses，students are likely to get higher earnings in later years．The students are more likely to stay in school，graduate and go on to higher education．

In Germany，students as young as 13 and 14 are expected to do internships．German companies work with schools to make sure that young people get the education they need for future employment．

But in America, education reform programs focus on how well students do in exams instead of bringing them into contact with the working world．Harvard Education school professor Robert Schwartz has criticized education reformers for trying to place all graduates directly on the four-year college track．Schwartz argued that this approach leaves the country’s most vulnerable(易受影响的)kids with no jobs and no skills．

Schwartz believed that the best career programs encourage kids to go for higher education while also teaching them valuable practical skills at high school．James Madison High School in New York，for example，encourages students to choose classes on career—based courses．The school then helps them gain on—the-job experience in those fields while they’re still at high school．

However，even for teens whose schools encourage them to connect with work，the job market is daunting．In the US，unemployment rates for 16-to 19-year-olds are above 20 percent for the third summer in a row．

“The risk is that if teenagers miss out on the Summer job experience，they become part of this generation of teens who had trouble in landing a job，”said Michael，a researcher in the US.

1.In the author’s opinion, American high school leavers__________.

2.According to Robert Schwartz，_________.

3.What can be inferred from the text?

4.What’s the main idea of the text?

5.The underlined word “daunting” in Paragraph 6 most probably means___________.

高二英语阅读理解极难题查看答案及解析

Green tree ants are important builders in the rainforest. They’re like the worker bees of the ant world. The native forest of Thala Beach Nature Reserve is the natural home of these insects.

They climb all over the tree that contains their nest and protect it from enemies with great fierceness. The ants are often in the fruiting trees of Tropical North Queensland. When an animal tries to help themselves to some tasty fruit, they find themselves attacked by a powerful, frightening army of green tree ants! Their bite is not very painful but many ants attacking at the same time can be extremely uncomfortable.

The nests are large and constructed by sticking the leaves at the end of branches together to create a home looking roughly like a globe. Most of the nest construction and weaving is conducted at night. A mature colony of green tree ants can hold as many as 100,000 to 500,000 workers and may include as many as 12 trees and contain as any as 150 nests. Green tree ant colonies have one queen and a colony can live up to eight years.

However, the ants are so busy that they fail to spot a dishonest figure. There is a spider called the Salticid spider, or the jumping spider, as they are sometimes referred to, which has excellent eyesight and is only active during daylight, weaving a protective covering of silk to spend the night in. Interestingly, the Salticid spider does not look like a green tree ant. Instead, it chemically copies green tree ants’ smell. Effectively pretending to be an ant, it goes into the green tree ants’ nest, enters the nursery and feasts on their babies. Green tree ants don’t have good eyesight and smell everything with their antennae (two long thin parts on an ant’s head). Therefore, the ants think the spider is another ant and ignore its presence within the nest.

Next time, as you wander around Thala’s native forest, keep an eye out for these busy little creatures. Look up into the trees and you’ll likely spot their nests.

1.What does Paragraph 2 tell us about green tree ants?

A. They often start wars for food.　　 B. They like tasty fruit very much.

C. They leave painful bites.　　 D. They have good defenses.

2.What is special about the green tree ant’s nest?

A. It takes years to weave a nest.　　 B. It is reconstructed yearly.

C. It is made of leaves.　　 D. It can hold up to 500,000 ants.

3.Why do green tree ants regard the spider as another ant?

A. It can communicate with them.　　 B. It can make familiar sounds.

C. It has a similar smell.　　 D. It has an ant’s appearance.

4.What can we say about the Salticid spider?

A. It is the green tree ant’s enemy.　　 B. It helps the green tree ant build bests.

C. It is harmful to fruiting trees.　　 D. It protects the green tree ant.

高二英语阅读理解中等难度题查看答案及解析

Suppose you work in a big firm and find English very important for your job because you often deal with foreign businessmen. Now you’re looking for a place where you can improve your English, especially spoken English.

Here are some ads about English language training from newspapers. You may find the information you need.

Global English Center

﹡General English in all four skills: listening, speaking, reading and writing.

﹡3-month (700yuan), 6-month (1,200yuan) and one year (2,000yuan) courses.

﹡Choice of morning or evening classes, 3 hours per day, Mon.---Fri.

﹡Experienced college English teachers.

﹡close to city center and bus stop.

Tel: 67605272     Add: 105 Zhongshan Road, 100082

Modern Language School

﹡Special courses in English for business, travel, banking, hotel management and office skills.

﹡Small classes (12-16 students) on Sat. & Sun. from 2:00p.m.---5:00p.m.

﹡Native English teachers from Canada and USA.

﹡Language lab and computer supplies.

﹡3-month course: 1,050 yuan.

﹡6-month course: 1,850 yuan.

Write or phone: Modern Language School, 675 Park Road, 100056

Tel: 67353019

The 21^st Century English Training Center

﹡We specialize (专门研究) in effective teaching at all levels.

﹡We offer morning or afternoon classes, both of which last three months and a half at a cost of 800 yuan.

﹡We also have a six-week TOEFL preparation class during winter and summer holiday.

﹡Entrance exams: June 1 and December 1.

﹡Only 15-minute walk from city center.

Call 67801642 for more information.

The International House of English

﹡Three/ Six-month English courses for students of all levels at a very low cost: 60 yuan for 12 hours per week; convenient class hours: 9:00a.m. –12:00a.m. and 2:00p.m.—5:00p.m.

﹡A four-month evening programme for developing speaking skills (same cost as day classes).

﹡Well-trained Chinese and foreign teachers experienced in teaching English as a second/ foreign language.

﹡Free sightseeing and social activities.

For further information call 57432308.

1.You work from 9:00a.m. to 4:30p.m. every day. Which school will you choose?

A. Global English Center and Modern Languange School.

B. Global English Center and the International House.

C. Modern Languange School and the 21^st Century.

D. The 21^st Century and the International House.

2.The 21^st Century’s difference from the other three schools is that ________ .

A. its teaching quality is better

B. it is nearest to the city center

C. its courses are more advanced

D. it requires an entrance examination

3.You will probably prefer to go to the International House because it ________ .

A. offers sightseeing and social activities

B. has a special course in spoken English

C. costs less than the other schools

D. has native English teachers

4.Modern Language School runs only _______ .

A. big classes     B. special classes     C. normal classes     D. small classes

高二英语阅读理解简单题查看答案及解析