1 . When lightning caused fires around California’s Big Basin Redwoods State Park north of Santa Cruz in August 2020, the fire spread quickly. Mild fires strike coastal redwood (红杉) forests about every decade. The giant trees resist burning thanks to the bark (树皮), up to about 30 centimetres thick at the base, which contains acids. Their branches and needles are normally beyond the reach of flames. But this time flames shot through the top of 100-metre-tall trees, burning the needles. “It was shocking,” says Drew Peltier, a tree expert at Northern Arizona University. “It really seemed like most of the trees were going to die.”
Yet many of them lived. In a paper published yesterday in Nature Plants, Peltier and his colleagues help explain why: The survivors use long-held energy reserves—sugars that had been made from sunlight decades earlier—and poured them into buds (芽) that had been lying dormant (休眠的) under the bar k for centuries.
“This is one of those papers that challenges our previous knowledge on tree growth,” says Adrian Rocha, an ecosystem ecologist at the University of Notre Dame. “It is amazing to learn that carbon taken up decades ago can be used to sustain its growth into the future.” The findings suggest redwoods have the tools to cope with big fires driven by climate change, Rocha says. Still, it’s unclear whether the trees could cope with the regular infernos that might occur under a warmer climate environment.
The fire in 2020 was so intense that even the top branches of many trees burned and their ability to photosynthesize (光合作用) went up in smoke along with their pine needles. Trees photosynthesize to create sugars and other carbohydrates (碳水化合物), which provide the energy they need to grow and repair tissue. Trees do store some of this energy, which they can call on during a drought or after a fire. Although the redwoods have sprouted (长出) new growth, Peltier and other forest experts wonder how the trees will cope with far less energy from photosynthesis, given that it will be years before they grow as many needles as they had before the fire. “They’re alive, but I would be a little concerned for them in the future.”
1. What’s special about this big fire for coastal redwood forests in 2020?| A．It burnt the top of the trees. | B．It was very close to the last fire. |
| C．It resisted burning effectively. | D．It caused relatively minor damage. |
| A．Sugars protected their barks. | B．Energy reserves promoted the growth of buds. |
| C．They got used to hot climate. | D．They took in much carbon to resist fire. |
| A．Unpredictable disasters. | B．Changeable climate. |
| C．Terrible environment. | D．Uncontrollable fires. |
| A．Their tissues can’t be repaired. | B．They can’t save energy anymore. |
| C．Their energy saved is not sufficient. | D．They grow too slowly. |
2 . There are a number of animals that give off light in some way-including several kinds of insects and fish. Some kinds of mushrooms give off light, too. But most plants don’t give out light. Now, scientists are working to change that.
When a living thing gives off light, it’s called bioluminescence (生物发光). Fireflies are a well-known example of bioluminescence. Though less well-known, many mushrooms are also bioluminescent. These bioluminescent creatures light up thanks to the chemicals called luciferins (荧光素)inside their bodies. Luciferins cause a chemical reaction that can give off light.
Plants don’t naturally have luciferins, so there are no naturally bioluminescent plants. But that hasn’t stopped scientists from trying to create them. In the past, scientists have created plants that made less bright by adding DNA from shining objects. Scientists have also created plants that can give off light by adding luciferins to plants. But it only works as long as the chemicals last. In 2017, a team was able to cause a plant to give off light for about four hours.
Now, researchers at a Russian company have come up with a new method of creating shining plants. By adding certain parts of the DNA from shining mushrooms to ordinary tobacco plants, the researchers were able to create plants that could make their own luciferins. The scientists reported that the light was about 10 times brighter than in earlier shining plants.
The researchers believe that shining plants could help scientists learn more about the way plants work. For example, the moving patterns or waves of light in the plants may show activities in plants that normally can’t be seen. The shining also helps reveal how plants may be affected by things around them. For example, the plants gave off much more light strongly when a ripe banana skin was nearby. But the researchers don’t think the plants will just be used for science. They think many people may want shining plants for their beauty. So they are working with a company to develop shining plants for sale.
1. What phenomenon does the author describe in paragraph 1?| A．Most animals hate giving off light. |
| B．Many plants give off light through scientists’ efforts. |
| C．Animals give off light to protect themselves. |
| D．It’s hard to find plants that give out light. |
| A．It gives off lots of heat to warm itself. |
| B．It has chemical reactions inside its body. |
| C．It lacks energy due to chemical reactions. |
| D．It informs other fireflies of the danger. |
| A．By showing numbers. | B．By making a comparison. |
| C．By providing examples. | D．By making a summary. |
| A．Human development results in less shining plants |
| B．Scientists manage to create shining plants |
| C．People’s lifestyles are reflected in shining plants |
| D．Geography determines the types of shining plants |
3 . On the streets of Manhattan and Washington, D. C., in neighborhoods in Seoul and parks in Paris, ginkgo (银杏) trees are losing their leaves in reaction to the first gust of cold winter air. This leaf drop, gradual at first, and then sudden, carpets streets with golden, fan-shaped leaves. Scientists are documenting evidence of the event happening later and later, a possible indication of climate change. But the story of ginkgos is not the familiar one of human carelessness with nature.
Thanks to fossils found in North Dakota, scientists found a ginkgo has genetically similar ancestors dating back 170 million years to the Jurassic Period. “It almost went extinct. Then humans rescued it and spread it around the world. It’s such a great evolutionary (进化) and cultural story,” says Peter Crane, a ginkgo expert.
One theory for the decline of the ginkgo species began 130 million years ago, when flowering plants began spreading. They grew faster and attracted more pollinators (传粉者) than ginkgos. “It’s possible that ginkgos were elbowed out of the way,” says Crane. Already competing to survive, ginkgos began to disappear during a time of global cooling that began around 66 million years ago. By the time the last ice age ended 11,000 years ago, the remaining survivors were found in China.
Ginkgo trees are smelly. “My guess is that they were eaten by animals that liked smelly things. They then passed through their body and grew.” Crane says. Those same seeds may have helped ginkgo find favor with humans 1,000 years ago. Once cleaned of their outer layer, ginkgo seeds are safe to eat. It’s then, when the trees had long since disappeared elsewhere, that people in China may have begun planting them and eating their seeds. Then gradually ginkgos spread across the world. Now it’s seemingly naturally resistant to insects and high levels of air pollution.
Crane isn’t worried about its future, though: The popularity of the species will help it survive. “Though its status in the wild may be difficult to access, it’s a plant that’s unlikely to ever go extinct,” he says.
1. What may have caused the further delay of ginkgo’s leaf drop?| A．The colder weather in winter. |
| B．The protection from city councils. |
| C．The global warming phenomenon. |
| D．The careless interaction with humans. |
| A．The reasons why ginkgos almost died out. |
| B．The advantages of ginkgos over other plants. |
| C．The theories of experts for multiplying ginkgos. |
| D．The competition between various flowering plants. |
| A．Their eatable seeds. | B．Their unpleasant smell. |
| C．The natural evolution. | D．The careful planting. |
| A．Worried. | B．Optimistic. | C．Uncertain. | D．Hopeless. |
4 . Recent research confirms what our farming ancestors have known for centuries about hedges (树篱). They conserve precious soil by acting as windbreaks and absorbing rainwater that would otherwise wash it from the fields. And hedges store carbon, putting them in the front line of our bi d to tackle the climate crisis.
However, hedges have had a tough time in the poor countryside, with farmers encouraged to tear them down in pursuit of maximum production and larger field s to accommodate ever-larger machinery. What’s more, some hedges have been ignored. If left to their own devices, they’ll eventually become a line of trees. Some hedges each year lose their structures and fail to fulfil the primary duty as a barrier. Around a half of the nation’s hedges have disappeared in the past century.
There are signs that “the tide is turning”. The search for net zero has aroused many organizations’ interest in the humble hedge’s role as a carbon sink. The Climate Change Committee is recommending a 40 percent increase in hedges: an additional 200,000 km. Such recommendations are starting to drive policy. Cash-pressed farmers will be encouraged to create new hedges and improve their management of existing ones under the new Environmental Land Management Schemes, which will replace many of the existing agricultural support payments in coming years. Meanwhile, initiatives such as Close the Gap, led by the Tree Council, is providing funding and support to plug the gaps in existing hedges with new planting. There’s even an app to help time-pressed farmers do a quick survey to spot where their hedges need some help.
This is a good time for hedges. Take some of the most pressing challenges facing the countryside, and indeed, the world as a whole — the climate crisis, soil erosion (侵蚀), insect attack and wider biodiversity loss — and hedges are part of the solution.
1. What does recent research show about hedges?| A．They are unique landscapes in the rain. |
| B．They act as dividing lines between fields. |
| C．They have long been helpful to agriculture. |
| D．They are frequently washed away from the fields. |
| A．Their suffering. | B．Their production. |
| C．Their duties. | D．Their structures. |
| A．Puzzled. | B．Concerned. | C．Humble. | D．Indifferent. |
| A．Hedges: Ancient Resources |
| B．Hedges: Official Recommendations |
| C．Restoring Hedges: Bringing Benefits to the Environment |
| D．Researching Hedges: Originating from Farmers’ Request |
5 . Mangroves (红树林) grow on the boundary between land and sea. Rooted in the soil exposed to sea water, they support a rich biodiversity and provide a valuable nursery for some sea animals like fish, supporting the food security of coastal communities. More importantly, they can resist natural disasters, thus keeping communities and structures safe and sound.
Over time, these exceptional trees have adapted to withstanding or recovering from the impact of natural disasters such as storms and tsunamis (海啸). When waves pass through mangrove forests, the above-ground roots and branches of the trees reduce wave height and energy. This decreases the waves’ ability to consume the soil and damage coastal buildings, while reducing the risk of flooding for low-lying areas behind the mangrove forests. Over a distance of 100m, wave heights can decrease between 13% and 66%. Over a distance of500m, mangroves can reduce the height of waves by 50% to 99%.
Dense (茂密的) mangrove forests also reduce wind speeds locally, which has the added advantage of preventing waves in and immediately behind the mangroves. This can potentially reduce its hazard to nearby facilities.
There is growing evidence that mangroves can reduce the impact of tsunamis by lowering the destructive energy of water flowing inland. This was the case notably during the Indian Ocean tsunami in 2004. Mangrove belts, which are several meters wide, have been shown to decrease tsunami wave height by between 5% and 30%. Wide and dense mangrove forests can also limit the area flooded by tsunamis, However, tsunamis over 4 meters deep may be taller than the mangroves and able to damage or even destroy these trees. Therefore, engineered structures are rarely built to the height of mangroves.
Some mangrove trees can grow up to 60m in height, depending on the species, climatic conditions and available nutrients. Some mangroves also exist as short plants. They are found in the coastal areas of the Americas, Africa, the Middle East and Asia-Pacific. It is estimated that more than three-quarters of the world’s mangroves are now threatened by coastal development, overexploitation, waste disposal and other pressures.
1. What enables mangroves to reduce wave height and energy according to paragraph 2?| A．The surrounding soil. | B．Their rich biodiversity. |
| C．The high-lying areas ahead. | D．Their natural structure. |
| A．Response. | B．Contribution. | C．Attachment. | D．Threat. |
| A．To prove mangroves can fight against tsunamis. | B．To say engineered structures are easily destroyed. |
| C．To show the harmful results brought by tsunamis. | D．To explain the gradual formation of coastal disasters. |
| A．Mangroves: the Mirrors of Natural Disasters | B．Mangroves: the Heroes of Coastal Protection |
| C．Mangroves: Seriously Threatened Plant Species | D．Mangroves: Shelters for Endangered Sea Animals |
6 . Farming today not only sends out greenhouse gas but destroys wildlife habitats. Agriculture now takes up half of Earth’s hospitable land surface, at the expense of these habitats. So I hope to restore current farmland to its natural state by ending the vegetation (植被) stage of crop-growing.
My PhD research at Wageningen University in the Netherlands is inspired by alternative, indoor methods of food production, such as farming leafy green vegetables vertically (垂直地) and growing meat in a laboratory. I wondered — if you can grow meat without an animal, can you grow fruit without a plant? This could be done inside, which might help us to return some agricultural land to nature.
During my master’s programme in agricultural engineering, I discussed indoor fruit production with my professor. He eagerly invited me to write a master’s paper on the subject of growing fruits without the plant.
The main task of my PhD is to collect immature fruit or flowers from tomato plants, and try to grow the stems (茎) into healthy, high-quality tomatoes in the lab. Ultimately, we want to produce fruit from tomato undifferentiated cells from which new plant organs can grow — and skip using a plant entirely.
I had achieved some early results of my research, when I was testing different growing conditions at different stages of tomato development. The lighting is an energy-efficiency measure; we use blue and red LEDs, the best colours for photosynthesis.
Some people get excited about the possibilities of my work, but most are doubtful, which I understand. In the past, people have rushed into using food technologies, such as cage-grown chickens and the extensive use of fertilizer, without considering the potential downsides. An important part of my PhD programme will be to assess the sustainability of my method.
1. What can we learn about farming today from the first paragraph?| A．It’s demanding. | B．It’s conventional. |
| C．It’s unsustainable. | D．It’s transformative. |
| A．He expressed great enthusiasm. | B．He rejected it immediately. |
| C．He began to do an experiment. | D．He asked him to stop researching. |
| A．To clarify others’ confusion. | B．To test out his own idea. |
| C．To produce more tasty food. | D．To voice his views on plants. |
| A．Approving. | B．Negative. | C．Indifferent. | D．Unclear. |
7 . Indoor plants might look as if they just sit around not doing much, but in many ways they are the unsung heroes of the home.
What are indoor plants?
Indoor plants, also known as houseplants or pot plants, are plants that like to grow indoors. Many of these species (物种) are not ideally suited to growing outside in the UK, especially in the winter.
Why are indoor plants good for you?
Will Spoelstra, who works at the Royal Botanic Gardens, says, “
Which plants can you grow?
Aloe vera, peace lilies and spider plants are some of the species that are easy to grow indoors. You can buy plants from supermarkets, garden centres or online. Younger plants are often cheaper than fully grown ones, and you get to care for them as they mature — which is part of the joy of owning plants. “
| A．All plants are different |
| B．Not only do they look beautiful |
| C．There are many benefits to growing plants indoors |
| D．Instead, they grow better inside, where it is warmer |
| E．Plants like peace lilies and devil’s ivy are among the best |
| F．Changing the pot of your plant from time to time will also help |
| G．Learning about the requirements of each plant can be very rewarding |
8 . A study finds that urban trees can survive increased heat and insect pests fairly well — unless they are thirsty. Lack of water not only harms trees, but allows other problems to have an extra effect on trees in urban environments.
“We would see some vibrant urban trees covered in scale insects (甲壳虫),” says Emily Meineke, a researcher at Harvard and first author of a paper on the study. “We wanted to know what allowed these trees to deal with these pests so much more successfully.”
The researchers collected detailed data on 40 urban willow oaks over the course of two years. The data included temperature, how water-stressed the trees were, and the density (密度) of scale insects which are well-known tree pests.
They also conducted laboratory experiments using willow oak seedlings. In these experiments, the researchers controlled the temperature, water and the presence of scale insects. They found that higher temperatures could actually have a positive effect on tree growth, as long as the trees had adequate water. And scale insects had little or no bad effect on the trees if the trees were not water-stressed. They also found that water stress limited tree growth all by itself. But the presence of increased heat and/or scale insects, when combined with water stress, had a multiplier effect — limiting growth far more than water stress or scale insects alone.
“This tells us that management strategies aimed at increasing tree hydration (水合作用) in cities may reduce the bad effects of all three of these key stressors,” says Meineke. “And that is likely to become increasingly important as water availability, temperature and pest abundance are affected by further urbanization and climate change. ”
“For example, urban planners should design urban landscapes that keep storm water in vegetation; invest in hydration strategies, such as appropriate soil quality and soil volume; and plant drought-tolerant tree species in the hottest parts of their cities,” says Frank, an associate professor of entomology.
1. What does the underlined word “vibrant” in paragraph 2 probably mean?| A．Weak. | B．Broken. | C．Full of years. | D．Full of life. |
| A．Threats to urban trees. | B．The researchers’ findings. |
| C．The effects of water on cities. | D．The protection of urban trees. |
| A．By controlling insects. | B．By stopping city expanding. |
| C．By lowering the temperature. | D．By increasing tree hydration. |
| A．To reduce pollution in big cities. | B．To offer advice to urban planners. |
| C．To promote common knowledge. | D．To find effective ways of planting. |
9 . Scientists have discovered what they believe is the world’s largest plant, an underwater field of sea grass that stretches for 1.12 miles off the west coast of Australia. This huge meadow (草地) has spread widely all through Shark Bay. The sea grass plant is believed to be around 4, 500 years old.
Many plants create new plants by growing flowers and spreading seeds. The DNA of the plants that grow from these seeds is slightly different from the DNA of the plants that the seeds came from. By comparing the DNA from their samples, the scientists hoped to get an idea of how many different sea grass plants there were in the meadow.
What they learned shocked them — all of the grass samples had almost exactly the same DNA. That meant that they were all just one plant, one big sea grass plant spreading out over 77 square miles. This makes it the largest known plant in the world by far.
So how has the Shark Bay sea grass grown so large? Instead of spreading with flowers arid seeds, it spreads by cloning (克隆) itself. As its roots spread out under the sea floor, new plants shoot up from those roots.
The sea grass in Shark Bay is also unusual in another way. It’s a “polyploid”. Usually, an organism (有机体) has two parents, and gets half of its DNA from each. But polyploid organisms have all of the DNA from both parents, meaning they have twice as much DNA. The scientists think the extra DNA may make it easier for the sea grass to survive in difficult conditions.
The Shark Bay sea grass generally grows and spreads about 14 inches a year. Because of the history of Shark Bay and the rate of growth, the scientists believe that the plant is about 4, 500 years old.
1. Why do scientists compare the DNA of the sea plants?| A．To find ways to protect sea plants. |
| B．To discover the diversity of sea plants. |
| C．To identify the oldest plants in the sea. |
| D．To explore the unknown ocean resources. |
| A．Its DNA cannot be cloned. |
| B．It blooms and bears many seeds. |
| C．Its roots are a connected whole. |
| D．It is the fastest growing grass in the world. |
| A．Gaining the ability to grow bigger. |
| B．Getting parts of the parents’ DNA. |
| C．Having an advantage over every sea plant. |
| D．Being more adaptable to tough conditions. |
| A．Genetic Changes in Sea Grass | B．Ecological Status of the Sea Floor |
| C．Scientists Found World’s Largest Plant | D．New Underwater Grass Is Discovered |
10 . Indoor plants are a beautiful way to brighten up your home, especially in the gray months of winter. But there can be a dark side to houseplants if you have children or if children visit your home. I’s important that you know which plants are poisonous to them.
Gardening expert Jessica Damiano often points out houseplants in friends’ homes should be kept out of children’s mouths. “I don’t mind ruining friends’ hopes of a beautiful indoor jungle if it means preventing harm,” Damiano said.
America’s Poison Centers in Arlington, Virginia get an average of 33,000 calls a year from people whose kids put different plants in their mouths. The cases usually involve children under 3 because they would explore their environment and put everything in their mouths. Most accidental exposures aren’t serious. But in some cases a child’s breathing, skin and eyes can be badly harmed.
Damiano recently visited her cousin’s home and saw a dieffenbachia plant in the kitchen. Her cousin told her that her young son, who had just begun crawling (爬), had shown interest in the leaves. Damiano had to explain to her cousin that eating a small amount of the plant’s stem (茎) can cause temporary but severe pain. The plant parts can cause throat and mouth swelling. The plant’s sap (树液) can cause nose, skin and eye pain. Other plants that can cause similar reactions include: caladium, flamingo flower, Swiss cheese plant, peace lily and pothos.
Damiano said that parents should teach their young children not to put non-food plant parts into their mouths. Besides, she urges parents to research whether the plants in their homes are safe to grow around children. She also suggests learning the official botanical names of houseplants so that they’re able to provide that information quickly to a poison control expert, if needed.
Not all houseplants are problematic, of course. Spider plants are nontoxic (无毒的) and are also among the easiest indoor plants to grow. African violets, Boston ferns and Christmas cactus are other safe choices.
1. Why are children under 3 more likely to become victims of houseplants?| A．They have easier access to houseplants. |
| B．They enjoy tasting anything out of curiosity. |
| C．They tend to mistake houseplants for candies. |
| D．They are more sensitive to poison of any kind. |
| A．Its sap can lead to pain in the skin. |
| B．Its stem can cause long lasting pain, |
| C．It harms health only when eaten a lot. |
| D．It looks like the peace lily in appearance. |
| A．They should avoid growing houseplants. |
| B．They should ask their children not to touch plants. |
| C．They should teach themselves knowledge about houseplants. |
| D．They should keep in close touch with poison control experts. |
| A．How to Choose Safe Houseplants’ |
| B．How to Decorate Houses with Plants |
| C．Keep Young Children Away from Houseplants |
| D．Watch Young Children around Some Houseplants |
