Redwood trees are the tallest plants on the earth,reaching heights of up to 100 meters.They are also known for their longevity,typically 500 to 1000 years,but sometimes more than 2000 years.A hundred million years ago,in the age of dinosaurs,redwoods were common in the forests of a much more moist and tropical North America.As the climate became drier and colder,they declined to a narrow strip along the Pacific coast of Northern Califomia.
The trunk of redwood trees is very strong and usually forms a single straight column.It is covered with a soft bark.This bark can be pretty thick,well over two feet in the more mature trees.It gives the older trees a certain kind of protection from insects,but the main benefit is that it keeps the center of the tree harmless from moderate forest fires because of its thickness.This fire resistant quality explains why the giant redwood grows to live that long.While most other types of trees are destroyed by forest fires,the giant redwood actually prospers because of them.
Moderate fires will clear the ground of competing plant life,and the rising heat dries and opens the ripe fruit of the redwood,releasing many thousands of seeds onto the ground below.
New trees are often produced from shoots,little baby trees,which form at the base of the trunk.These shoots grow slowly,fed by the root system of the “mother’’ tree.When the main tree dies,the shoots are then free to grow as full trees,forming a “fairy ring” of trees around the original tree.These trees,in turn,may give rise to more shoots,and the cycle continues.
1.Why were redwood trees easier to find in the forests of North America millions of years ago?
A.The trees were taller and stronger.
B.The soil was softer for seeds to develop.
C.The climate there was warmer and wetter.
D.The temperature was lower along the Pacific coast.
2.Which of the following is a function of the tree bark as mentioned in the passage?
A.It allows redwood trees to bear seeds.
B.It prevents redwood trees from attack by insects.
C.It helps redwood trees absorb water in the air.
D.It makes redwood trees more beautiful and appealing.
3.Why do redwood trees grow to live that long according to the passage?
A.They have heavy and straight tree trunks.
B.They are properly watered and catered to.
C.They are more resistant to fire damage than other trees.
D.They produce many young trees to maintain their life cycle.
4.How does a “fairy ring’’ form according to the passage?
A.By killing an old tree. B.By connecting root systems.
C.By inserting holes into old trees. D.By surrounding a mature tree.
高三英语阅读理解中等难度题
Redwood trees are the tallest plants on the earth,reaching heights of up to 100 meters.They are also known for their longevity,typically 500 to 1000 years,but sometimes more than 2000 years.A hundred million years ago,in the age of dinosaurs,redwoods were common in the forests of a much more moist and tropical North America.As the climate became drier and colder,they declined to a narrow strip along the Pacific coast of Northern Califomia.
The trunk of redwood trees is very strong and usually forms a single straight column.It is covered with a soft bark.This bark can be pretty thick,well over two feet in the more mature trees.It gives the older trees a certain kind of protection from insects,but the main benefit is that it keeps the center of the tree harmless from moderate forest fires because of its thickness.This fire resistant quality explains why the giant redwood grows to live that long.While most other types of trees are destroyed by forest fires,the giant redwood actually prospers because of them.
Moderate fires will clear the ground of competing plant life,and the rising heat dries and opens the ripe fruit of the redwood,releasing many thousands of seeds onto the ground below.
New trees are often produced from shoots,little baby trees,which form at the base of the trunk.These shoots grow slowly,fed by the root system of the “mother’’ tree.When the main tree dies,the shoots are then free to grow as full trees,forming a “fairy ring” of trees around the original tree.These trees,in turn,may give rise to more shoots,and the cycle continues.
1.Why were redwood trees easier to find in the forests of North America millions of years ago?
A.The trees were taller and stronger.
B.The soil was softer for seeds to develop.
C.The climate there was warmer and wetter.
D.The temperature was lower along the Pacific coast.
2.Which of the following is a function of the tree bark as mentioned in the passage?
A.It allows redwood trees to bear seeds.
B.It prevents redwood trees from attack by insects.
C.It helps redwood trees absorb water in the air.
D.It makes redwood trees more beautiful and appealing.
3.Why do redwood trees grow to live that long according to the passage?
A.They have heavy and straight tree trunks.
B.They are properly watered and catered to.
C.They are more resistant to fire damage than other trees.
D.They produce many young trees to maintain their life cycle.
4.How does a “fairy ring’’ form according to the passage?
A.By killing an old tree. B.By connecting root systems.
C.By inserting holes into old trees. D.By surrounding a mature tree.
高三英语阅读理解中等难度题查看答案及解析
Samuel, the tallest boy in our class, ______ easily reach the books on the top shelf.
A. must B. should C. can D. need
高三英语单项填空中等难度题查看答案及解析
Many of the earth’s plants and animals have already ______ and several other species are endangered.
A.died away B.died out C.died down D.died of
高三英语单项填空中等难度题查看答案及解析
Scientists in the United States say plant life has increased on Earth in the past twenty years and that in every area of plant growth the increase is the result of weather conditions.
Eight scientists from across the United States did the study. The space agency NASA and the Department of Energy paid for it. The findings were published in the magazine Science.
The researchers spent one and a half years examining weather satellite information. The information was recorded from 1982 to 1999. That period was one of the warmest on record. Researchers found that rainfall generally increased during that time.
The satellites measured the number of leaves on plants and the amount of sunlight taken in. The scientists used that information to estimate what is called net primary production. This is total amount of carbon stored in land plants.
The scientists report a 6% increase in stored carbon since 1982. They say gains were high in equatorial areas, especially around the Amazon River in South America. The area alone had a 1% increase in the net primary production.
Ramakrishna Nemani of the University of Montana in Missoula headed the study. He says reduced cloud cover led to growth in Amazon area. He also says the lack of clouds allowed more sunlight to get through. More sunlight meant increases in photosynthesis(光合作用). That is the process by which plants use energy from sunlight to produce the chemicals they need to grow.
Northern Canada, the north-central United States and northern Europe were second in increased plant growth. Ramakrishna Nemani says a rise in temperature helped plants there.
All together, the report says 25% of areas of plant life on Earth experienced increases. But the scientists also note increase in the number of people on Earth and carbon dioxide levels in the atmosphere. Ranga Myneni of Boston University in Massachusetts, another study scientist says humans use about half the net primary production on Earth. And he notes that the world population grew by 36% during the period of time studied.
1.Which of the following is in charge of the study?
A. The space agency NASA of the US.
B. The Department of Energy of the US.
C. Ramakrishna Nemani in Missoula.
D. Ranga Myneni in Massachusetts.
2.What’s the main cause of the plant growth put forward by the study?
A. Growth in population.
B. Regional features.
C. Seasonal variation.
D. Weather conditions
3. Why do scientists believe that reduced cloud cover has led to the plant growth in the Amazon area?
A. Because plants could take in more sunlight.
B. Because plants could get more rainfall.
C. Because plants could enjoy cooler air.
D. Because plants suffer less from natural disasters.
4. Which of the following descriptions about the years from 1982 to 1999 is TRUE?
A. It was the warmest on record.
B. Rainfall decreased little by little.
C. World population grew by 25%.
D. Stored carbon increased by 6%.
高三英语阅读理解简单题查看答案及解析
It is the protection for the trees___________ really matters, rather than how many trees are planted.
A.what | B.that |
C.不填 | D.which |
高三英语单项填空简单题查看答案及解析
LONDON: What could possibly be wrong with planting trees? The benefits are obvious; they firm the soil, soak up (摄取) extra water and take carbon dioxide (二氧化碳) out of the atmosphere.
However, it now turns out that planting trees could add to global warming.
Tree roots do a great job of keeping soil firmly on the ground and out of the wind’s power. The problem is that some of those dust clouds play an important part in taking in carbon dioxide.
Huge dust storms blow out over the oceans from dry parts of North Africa and central Asia. Tons of dust are lifted and left as a thin film over the ocean surface. The dust fuels oceanic life.
Dust from China is carried east and left in the Pacific Ocean. If a tree-planting programme there is successful and the dust supply reduced, the final result may be that less carbon dioxide gets locked away in the ocean.
Andy Ridgwell, an environmental scientist from the University of East Anglia, has spent the past few years studying dust and says his work “shows clearly the complexity of the system and the importance of not tinkering(粗劣地修补) with it without understanding the results. For this reason the need is to focus(集中) on cutting carbon dioxide giving off rather than monkeying (瞎弄) about with the land surface.”
An American scientist, Robert Jackson, has shown that when native grassland areas are invaded(侵入) by trees, carbon is lost from the soil. “We are studying why the soil carbon disappears, but one theory is that trees do a lot more of their growing above ground compared to grasses, so less carbon goes directly into the soil from trees, ” says Jackson.
In wet areas of the world, the gain from trees absorbing carbon dioxide above ground seems to be outweighed(超过) by the loss of carbon from the soil below ground. Countries that plan to combat global warming by planting trees may have to think again.
Solutions to environmental problems are often more complex than they first appear, and understanding the Earth’s climate is a very great challenge.
1.People usually hold the opinion that_____________.
A. huge dust storms can destroy carbon dioxide
B. huge dust storms can destroy the oceans on the earth
C. huge dust storms can’t do anything beneficial for man
D. planting trees is the only way to control huge dust storms
2. Andy Ridgwell, the environmental scientist, believes that_____________.
A. dust plays a more important part than trees
B. trees shouldn’t have been planted in dry places
C. carbon dioxide is harmful to everything on the earth
D. environmental problems are more complex than expected
3. Robert Jackson’s experiment proves that_____________.
A. grassland areas should be covered by forests
B. trees hold more carbon than grasses
C. carbon can turn grass into dust
D. less carbon can make trees grow faster
高三英语阅读理解中等难度题查看答案及解析
29. On March 12, the students were planting trees ____ the classroom.
A.in the back of | B.at the back of | C.to the back of | D.on the back of |
高三英语单项填空简单题查看答案及解析
The bristlecone pine is the longest-living thing on the earth. These trees, with their strangely-shaped, wind-beaten limbs(枝干), can live up to 5,000 years. But experts worry that a warming climate in some areas may threaten its future.
Researchers say warmer weather is permitting a similar kind of tree, the limber pine, to take over good growing places from the ancient bristlecone. They say the tree is being crowded out of mountainous areas where it grows.
“The bristlecone pine is the oldest individually growing organism,” researchers say. They grow in high mountain forests in eastern California, Nevada and Utah. In those mountains, the trees face high winds and extreme temperatures, which leave them with twisted limbs and shapes. “Even in such tough conditions,” Brian Smithers, a researcher at the University of California, said, “the limber pine is taking all the good spots.”
The limber pine is the bristlecone’s distant relative and competitor. It can also live a long time——up to 2,000 years. And it is usually found at lower altitudes, where temperatures are warmer. However, according to a three-year study which centered on trees that have started growing in the last 50 years in California’s White Mountains, most of the trees growing at higher altitudes were limber pines.
Scientists compared the competing species to two o1d men in a very slow race up a mountainside. This race between such slow-growing trees takes thousands of years. They say climate change is causing the competition.
Smithers said the bristlecone pines are not in danger of disappearing. But he assumes they could be crowded out of some places where they have grown for thousands of years.
The researchers say the findings show how climate change can affect the two kinds of trees. The information, they say, can help scientists understand more complex forests.
1.What’s the function of Paragraph 1?
A. To introduce a topic. B. To summarize the whole passage.
C. To describe the appearance of a tree. D. To praise the hard work of the experts.
2.What does the underlined sentence in Paragraph 2 mean?
A. There will be older trees sent out of those mountains.
B. There will be more places covered with bristlecone pines.
C. There will be better limber pines replacing the ancient ones.
D. There will be fewer bristlecone pines growing in those areas.
3.According to the passage, the reason why limber pines can grow at higher altitudes is_________.
A. the high winds B. the difficult conditions
C. the changing climate D. the extreme temperatures
4.What is the researchers’ attitude towards the future of the bristlecone pine?
A. Positive. B. Concerned.
C. Enthusiastic. D. Indifferent.
高三英语阅读理解中等难度题查看答案及解析
People planted trees on the waste hills_________ water and soil loss.
A. to decrease B. decreasing
C. decreased D. decrease
高三英语单项填空中等难度题查看答案及解析
—It ________ to plant trees and grass on the hillside.
—Yes. They help stop soil from being washed away.
A. makes sense B. makes money
C. makes a living D. makes a mistakes
高三英语单项填空中等难度题查看答案及解析