1 . Fungi (真菌) play an important role in ecosystems, are a source of food, and make key contributions to the world of medicine.     1    

An estimated two million fungal species — more than 90% of all fungi — have yet to be described by science, according to a science reporter.     2     Scientists are trying to find out more about this largely unexplored world, but it is challenging. Dr Martyn Ainsworth, a senior researcher from Royal Botanic Gardens, Kew, in London, says, “We can grow a certain number in the lab.     3     This has held back a lot of research.”

    4     “A lot of people are afraid of poisonous mushrooms,” says Dr Jassy Drakulic, a plant pathologist, “but only a very small proportion of the thousands of species of fungi in the world can cause disease.” Most are harmless and often beneficial, called by some “the hidden helpers of our environment”. Some fungi provide food and shelter for wildlife, help plants absorb water and nutrients and recycle waste and dead matter. Other types of fungi grow on the roots of trees and plants, forming a huge underground network that helps nourish trees.     5    

So, next time you add mushrooms to your dinner, take a painkiller for a headache, or go for a walk through the woods, remember to thank the living things that made it all possible — fungi.

A．Are mushrooms a type of fungus?

B．So, why do we know so little about them?

C．Wetlands are important because they provide food and shelter for wildlife.

D．The fact that we know so little about fungi leads us to misunderstand them.

E．“Fungi are really the behind-the-scenes team doing all the work,” adds Dr Ainsworth.

F．But there is a whole host of fungi that we cannot grow in the lab.

G．In the UK, there are around 25,000 species of fungi — five or six times more than plants.

2 . Common water plant could provide a green energy source. Scientists have figured out how to get large amounts of oil from duckweed, one of nature’s fastest-growing water plants. Transferring such plant oil into biodiesel (生物柴油) for transportation and heating could be a big part of a more sustainable future.

For a new study, researchers genetically engineered duckweed plants to produce seven times more oil per acre than soybeans. John Shanklin, a biochemist says further research could double the engineered duckweed’s oil output in the next few years.

Unlike fossil fuels, which form underground, biofuels can be refreshed faster than they are used. Fuels made from new and used vegetable oils, animal fat and seaweed can have a lower carbon footprint than fossil fuels do, but there has been a recent negative view against them. This is partly because so many crops now go into energy production rather than food; biofuels take up more than 100 million acres of the world’s agricultural land.

Duckweed, common on every continent but Antarctica, is among the world’s most productive plants, and the researchers suggest it could be a game-changing renewable energy source for three key reasons. First, it grows readily in water, so it wouldn’t compete with food crops for agricultural land. Second, duckweed can grow fast in agricultural pollution released into the water. Third, Shanklin and his team found a way to avoid a major biotechnological barrier: For the new study, Shanklin says, the researchers added an oil-producing gene, “turning it on like a light switch”by introducing a particular molecule (分子) only when the plant had finished growing. Shanklin says, “If it replicates (复制) in other species-and there’s no reason to think that it would not — this can solve one of our biggest issues, which is how we can make more oil in more plants without negatively affecting growth.”

To expand production to industrial levels, scientists will need to design and produce large-scale bases for growing engineered plants and obtaining oil — a challenge, Shanklin says, because duckweed is a non-mainstream crop without much existing infrastructure (基础设施).

1. What can people get from duckweed firsthand?

A．Plant oil.	B．Stable biodiesel.
C．Sustainable water.	D．Natural heat.

2. What does paragraph 4 mainly convey?

A．Options for renewable energy.

B．Reasons for engineering genes.

C．The potential of revolutionary energy source.

D．The approach to avoiding agricultural pollution.

3. What is the decisive factor to mass-produce the plant?

A．Industrial levels.	B．Unique design.
C．Academic research.	D．Basic facilities.

4. What would be the best title for the text?

A．Duckweed Power	B．Duckweed Production
C．Genetic Engineering	D．Genetic Testing

3 . 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

4 . “How many of us as children have stared up at a church-like top of a giant tree and climbed it in wonder, which is a rally special part of our lives?” asks Bill Laurance, a tropical ecologist at James Cook University. “The leaves of big trees in forests are spreading out in all directions. We’re faced with organisms that have evolved for long periods of ecological stability.”

“There’s a lot to discuss on the issue,” says David Lindenmayer, a conservation ecologist at the Australian National University. “Climate change will mean that, in some forests, big trees won’t reach the same sizes they used to.” The effects of climate change, including long droughts, more invasive species and so on increase the simple physical challenges that big trees face in pulling water from their roots to their leaves and withstanding windstorms.

Lindenmayer and Laurance define “large, old trees” as the largest five percent mature trees within a species. The flexible definition means that in some forests, the large, old trees might be only 20 meters tall and 100 years old.

These large, old trees control the surrounding plant communities, affect water and nutrient distribution, and provide food and shelter for wildlife. “They’re really the breadbaskets of the forest,” says Laurance. “This is a very environmentally and ecologically important group of organisms, and they need special care and handling.” Determining the distribution and habitat requirements for large, old trees in the landscape is the first step towards ensuring their survival, “We have to ensure that what we’re thinking is long-term, to match the way these trees have existed for hundreds or even thousands of years,” says Laurance. “It’s going to be a real challenge to keep some places where there is still wildlife and the big church-like trees that we all really care about.”

1. How does the author lead in the topic of the text?

A．By definition.	B．By comparison.
C．By quoting someone’s words.	D．By drawing some conclusions.

2. What can we learn about big trees from paragraph 2?

A．They are affected by various factors.

B．They have become shorter but thicker.

C．They easily pull water from their roots.

D．They grow taller because of climate change.

3. Which of the following does Laurance want to express in the last paragraph?

A．The plants around control trees’ survival.

B．It is necessary to take good care of big trees.

C．Big trees mainly depend on wildlife for survival.

D．Planting big trees is the first step in forest protection.

4. What can be the best title for the text?

A．Protect Forest Giants

B．Keep Ecological Stability

C．Deal with Forest Organisms

D．Fight Against Climate Change