1 . Theoretically some trees could live forever, according to a recent essay that reviews growing evidence on long-lived trees.

Across the board, trees do not die so much as they are killed, write the authors of the review essay. Their killers are outer factors rather than old age alone. That is, there is no evidence that harmful genetic mutations (基因突变) occur over time or that trees lose their ability to continue to grow.

“Trees might live forever, but this does not happen,” says co-author Franco Biondi. “Tree killers include environmental risks such as droughts , wildfires, terrible weather and human behaviors such as woodcutting and fires set to clear forests for hunting or grassland.”

Tree longevity (长寿) interests researchers in part because trees and other plants remove carbon from the atmosphere, and older trees are thought to store more carbon than younger ones. The rings of old trees can also serve as an invaluable record of climate history, with wider rings indicating better years.

David Stahle, a geographer and tree longevity researcher at the University of Arkansas, takes issue with the belief that trees can possibly live forever. “The likelihood, all things being equal, that trees can live forever seems unlikely to me,” he says.

This hypothesis (假设) has become popular in the past 20 years as researchers continue to report having found little genetic evidence of aging in extremely old trees. And this is one of the review essay’s most important points. But evidence of aging could be out there and just not yet found.

1. What does the recent review essay mainly indicate?

A．There are a great variety of tree killers.	B．Trees could keep on surviving forever.
C．More trees die naturally than being killed.	D．Genetic mutations stop trees from growing.

2. Why does tree longevity interest researchers?

A．Because the way trees grow rings is more interesting.

B．Because trees make clearer climate records than other plants.

C．Because older trees contribute more to the environment.

D．Because younger trees are less likely to have genetic mutations.

3. What is Stahle’s attitude to the finding of the review essay?

A．Doubtful.

B．Uninterested.

C．Reserved.

D．Favorable.

4. What does the last paragraph suggest?

A．The assumption has been proved true.	B．Evidence of aging trees might exist.
C．Tree research has grown in the past 20 years.	D．Some key points disappear in the review essay.

2 . Regarded as the “loneliest tree in the world”, the Sitka spruce (云杉) on uninhabited Campbell Island lately has kept good company with a team of New Zealand researchers who believe it could help unlock secrets of climate changes.

The nine-meter-tall spruce holds the Guinness Record title for the “remotest tree” on the planet. It is the sole tree on the shrubby, windswept island, 700 kilometers south of New Zealand in the Southern Ocean. It’s the only tree for 222km around; its nearest neighbor grows on the Auckland Islands.

Although classified as an invasive species, for radiocarbon science leader at GNS Science, Dr. Jocelyn Turnbull, the tree could be a valuable tool to understand what is happening with the uptake of CO₂ in the Southern Ocean. In order to measure CO₂ concentrations, taking samples of the atmosphere is the best method, and can be complemented with radiocarbon dating samples of deep water. But it comes with limitations. “You can’t collect air that was there 30 years ago, because it is not there anymore,” Turnbull said, “So we came up with this idea of using tree rings. Plants, when they grow, take CO₂ out of the air by photosynthesis (光合作用) and they use that to grow their structures and the carbon from the air ends up in the tree rings.”

This is helpful when there is an abundance of established trees, but those are a rarity in the Southern Ocean. Enter the Sitka Spruce - the south most tree, and the team could find it would offer up good data. “It’s grown a lot faster than anything else in that region and the rings are bigger and easier to separate out and get a record form.”

As for the tree’s lonely status: the description may be in the eye of the beholder. “To get to the tree you have to walk through elephant seals and sea lions, penguins and albatross,” Turnbull said. “The tree doesn’t look lonely …it looks quite content actually.”

1. What is special about the tree?

A．It measures nine meters wide.

B．It is the only tree on a vast land.

C．It grows on the Auckland Islands.

D．It owns the Guinness title for the “loneliest tree”.

2. What can we learn from Paragraph 3?

A．CO2 builds up in the tree rings.

B．The Sitka spruce is a native species.

C．Samples from water are usually inaccessible.

D．Photosynthesis stops the plants absorbing air.

3. What may Turnbull support?

A．The tree coexists with a variety of animals.

B．The tree grows well because of suitable climate.

C．It’s unwise to use tree rings as an indicator of CO2.

D．It’s possible to measure previous CO2 concentrations directly.

4. What is the main idea of the text?

A．Trees are of great significance to scientific research.

B．The “loneliest” tree in the world is not lonely at all.

C．Global warming has a far-reaching impact on creatures.

D．A remote Sitka spruce may help us learn about climate changes.

3 . Tree-planting, intended to help draw down carbon dioxide from the atmosphere, has become a synonym (同义词) for climate action. In our constant focus on trees, we’ve developed a fixed understanding: Trees absorb carbon dioxide, end of story. The reality is that trees don’t grow well alone. They exist within complex communities, helped along by each other as well as the animals they coexist with. The woodland isn’t nature’s only carbon sink: Grasslands and oceans also help reduce the carbon level and rely on a healthy amount of biodiversity.

That’s what the paper, published in Nature, wants to get across. Co-author Oswald J. Schmitz, a professor of ecology at Yale University, said trees might not be able to do their carbon-uptake job efficiently without the right animals in their ecosystem. That’s because animals animate the carbon cycle through their behavior and roles in the ecosystem. He added that the very presence of wild animals could cause feedback effects that change the ecosystem’s capacity to absorb, release, or transport carbon.

In Serengeti, for instance, the sharp decline in wildebeest (角马) population s during the mid-20th century allowed grass to grow wildly, eventually promoting wildfires that consumed 80 percent of the ecosystem annually and led to a net release of carbon dioxide into the atmosphere. When disease management and bans on illegal hunting helped animal populations recover, a greater share of the carbon stored in plants was consumed by wildebeest and released as waste, keeping it in the system and restoring the grassland as a carbon sink.

Researchers rarely consider wildlife conservation as a strategy to increase an ecosystem’s carbon storage capacity, said Schmitz. “They think that animals either aren’t important enough or that you can’t take up carbon and conserve animals at the same time,” he said. “Our message is that you can and should. It can be a win-win for both biodiversity conservation and carbon uptake.” We need a full picture-with both trees and animals-to explore nature’s full potential.

1. What can we learn from the first paragraph?

A．Actions are needed to reduce carbon dioxide.	B．Trees are a quick solution to the climate crisis.
C．People are not thinking through trees properly.	D．Grasslands and oceans help maintain biodiversity.

2. What does the underlined word “animate” in paragraph 2 mean?

A．Activate.

B．Restart.

C．Disturb.

D．Break.

3. What does the author want to say by mentioning wildebeest?

A．The conservation of animals is still a serious issue.

B．Animals can swing the ecosystem’s capacity to store carbon.

C．Human impacts bring about the reduction in wildlife populations.

D．The increase in animal species causes a decrease in carbon uptake.

4. Which of the following is the best title for the text?

A．Animals Adjust Themselves to Climate Change

B．Woodland Isn’t the Only Carbon Sink on the Earth

C．The Serengeti Ecosystem Needs Urgent Improvement

D．Trees May Fail to Fulfil Their Duties without Animals

4 . 阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

A seed bank stores seeds to preserve genetic diversity; hence it is a type of gene bank. Many people may wonder     1     the seeds are stored. One of the major reasons is to preserve the genes that plant growers need to increase yield (产量), disease resistance, drought tolerance, nutritional quality, and the taste of crops. Another is to prevent     2     (lose) of genetic diversity in rare or endangered plant species in     3     effort to conserve biodiversity. Many plants     4     (grow) centuries ago by humans are used less frequently now; seed banks offer a way to preserve that historical and cultural value. Collections of seeds stored     5     constant low temperature and low water level are guarded against reduction of genetic resources which are otherwise maintained in field collections. These alternative “living” collections can     6     (damage) by natural disasters, outbreaks of disease,     7     war. Containing valuable information about evolved strategies to reduce plant stress, seed banks are considered seed     8     (library), and can help to create genetically modified (调整过的) versions of     9     (exist) seeds. The work of seed banks often span decades and even centuries. Most seed banks are     10     (public) funded and seeds are usually available for research that benefits the public.

5 . 阅读下面材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

Hawthorn (山楂) trees or bushes are a familiar sight in the UK, where they are often found     1    (plant) along the edges of fields or used as garden boundaries. In May, they produce     2    (bunch) of white flowers, followed by fresh red berries.

    3     its name suggests, the plant has large thorns (刺),     4    (make)it possible for self-protection. Both the flowers and the berries can be used     5    (medical) and are a traditional remedy (疗法) for heart conditions.

The use of hawthorn as a herbal medicine to protect the heart can be traced back for centuries. Its use     6     modern times dates from an Irish physician, who used it to treat heart diseases. This doctor guarded his secret remedy closely, and it was not until after his death that his remedy was examined     7    (find) how it worked. And it turned out to be an active ingredient made from the bright red berries of hawthorn.

Hawthorn is now a popular heart remedy throughout Europe. It can help to protect the blood system that feeds the heart. Hawthorn can also contribute to mild chest pains     8    (relieve). Some specialists suggest it may also     9    (apply) to reduce the extra fat in the blood system.

Hawthorn is regarded as one of the     10    (safe) herbal medicines and although side-effects such as sweating and tiredness have been reported, they are extremely rare.

6 . Seagrass meadows(海草床) are wonder plants growing beneath the sea. They feed and shelter sea life and are masterful at storing carbon. Thanks to the assistance of tiger sharks, a huge seagrass meadow in the Bahamas Banks was recently discovered, offering the world a tool to fight climate change.

Seagrass has usually been detected by Earth-orbiting satellites that identify darker patches in the blue water. In this study, tiger sharks were selected as research tools due to their highly consistent associations with seagrass ecosystems. They spend 70% of their time in seagrass meadows. The team equipped eight tiger sharks with satellite tags (电子跟踪器), seven sharks with camera tags, and used a 360-degree camera on a shark for the first time ever.

The data researchers collected was astonishing. The world’s largest seagrass ecosystem, measuring at least 66,900 square kilometers, has been discovered. This reflects a 41% increase from previous estimates of global seagrass. Seagrass can capture (捕获) huge quantities of carbon by photosynthesis (光合作用) and stores it on the seafloor. In terms of climate change, this is excellent news; seagrass is 35 times faster a removing carbon than tropical rainforests. When referred to global seagrass carbon stock estimates, the study indicates that seagrass in the Bahamas may contain 19.2% to 26.3% of all the carbon stored in seagrass meadows on Earth.

Yet seagrass meadows are rapidly disappearing, with over 92% of meadows in the UK gone, according to the World Wildlife Fund. Scientists are collecting seeds and trying to grow new seagrass meadows through restoration projects. This new discovery offers optimism and proves the importance of the ocean for healing.

The sharks led us to the seagrass ecosystem in the Bahamas, which we now know is likely the most significant blue carbon sink(蓝色碳汇) on the planet. What this discovery shows us is that ocean exploration and research are essential for a healthy future. The untapped potential of the ocean is limitless. These meadows can be protected and can be replicated (复制,仿制), offering hope for climate change around the globe.

1. Why were tiger sharks chosen as research tools?

A．They are more flexible than other sea animals.

B．They can quickly adjust themselves to the deep sea.

C．They have a strong connection with seagrass ecosystems.

D．They can be easily equipped with experimental devices.

2. What are the numbers in paragraph 3 mainly about?

A．The decline of global seagrass meadows.

B．The impact of climate change on sea life.

C．The rapid increase in the amount of carbon on Earth.

D．The potential value of the world’s largest seagrass ecosystem.

3. What are scientists doing to protect seagrass?

A．Planting more seagrass meadows.

B．Developing new technology to collect seeds.

C．Mapping the distribution of seagrass meadows.

D．Encouraging people to join in restoration projects.

4. Which could be the best title for the text?

A．The New Way of Removing Carbon

B．The Significance of Ocean Exploration

C．A New Discovery: World’s Largest Seagrass Meadow

D．Tiger Sharks: Scientists’ Essential Helper to Study Climate

7 . The cooling effect of trees reduces the surface temperature of European cities in the summer by up to 12°C in some regions. In contrast, green spaces without trees have an insignificant effect, according to a study that strengthens the case for tree planting to help cities adapt to global warming.

Jonas Schwaab at ETH Zurich in Switzerland and his colleagues used land surface temperature data collected by satellites to compare the temperature differences between areas covered by trees, treeless urban green spaces, such as parks, and urban constructions such as roads and buildings. They analysed 293 cities from across Europe.

The land surface temperature measured by satellites isn't the same as the air temperature, which is more closely linked to what humans would feel, says Schwaab. "Usually, the air temperature difference between tree-covered areas and built-up areas would be much smaller than the land surface temperature differences," he says.

The team found that tree-covered areas in cities have a much lower land surface temperature compared with surrounding areas. The differences were between 80C and 12C in central Europe and between 0°C and 4°C in southern Europe.

The cooling effect of trees comes largely trom shading and transpiration（蒸腾）. This process takes heat energy from the surrounding environment for evaporation（蒸发）, lowering the surrounding temperature. In the warmer climate of southern Europe, the soil is typically drier, so the cooling effect of transpiration is lower than in regions further north, says Schwaab.

The team also found that the cooling provided by treeless green spaces is insignificant, and in some instances green areas without trees can even be warmer than the surrounding urban areas.

Extreme heat is a growing problem for cities in Europe and elsewhere as the planet gets hotter. The findings show that trees can have a big influence on cities across Europe, but since the size of their effects varies, heat reduction strategies should be tailored to suit each region, says Schwaab.

1. What's the purpose of the study?

A．To measure land and air temperatures.	B．To suggest planting more trees in cities.
C．To make people aware of global warming.	D．To stress the importance of green spaces.

2. Why is the cooling effect of transpiration lower in southern Europe?

A．The soil is drier	B．The climate is coluer.
C．There're more green spaces.	D．There're more roads and buildings.

3. What might Schwaab suggest in the last paragraph?

A．Wet lands should be enlarged.	B．Dry soil should be reduced.
C．More roads should be built.	D．Solutions should be different.

4. Which of the following is a suitable title for the text?

A．Trees Cool the Land Surface Temperature of Cities.	B．Researchers Raise Solutions to Extreme Weather
C．High Tech Lowers Land Surface Temperature	D．Extreme Heat Does Harm to the Environment