1 . Suzanne Simard, a professor of forest ecology who called herself a “forest detective”, was raised in mountains in Canada. Few scientists make much impact with their PhD thesis, but, in 1997, she did just that. Her research on the “wood wide web” made the cover of Nature and transformed our understanding of forests. What was then a challenge to traditional ideas is today widely accepted.
A mushroom is the part of a fungus (真菌) that sticks up above the ground. Thin, white threads grow from its stem deep into the soil. These threads are called hyphae (菌丝). Hyphae connect themselves to tree roots. They also stretch from root system to root system, like an underground network. This network may go for miles. Hyphae pick up nutrients and water from soil. The fungus threads that connect to tree roots share their nutrients and water with the trees. In return, they sip a bit of the sugar the trees make. Sharing helps both trees and mushrooms live. It’s also how trees communicate.
When a tree is being eaten by bugs, it makes chemicals to shoo them away, sort of like bug repellent (驱虫剂). The chemicals travel through the tree, down its roots, and into the hyphae network. Other trees connected to the network taste the chemicals. That tells them a nearby tree is under attack, so they start to make their own bug repellent. Trees do more than share warnings through the hyphae. They also help each other. In the fall, paper birch trees drop their leaves and can no longer make sugar. So, a fir tree that stays green all winter uses the network to send extra sugar to the birch until spring comes again. This system of sharing information and nutrients through the hyphae is sometimes called the “wood wide web”, because it works a bit like the Internet.
Local climate sets the stage for the wood wide web, researchers say. In cool temperature and boreal forests, where wood and organic matter decay slowly, network-building EM fungi rule. By contrast, in the warmer tropics where wood and organic matter decay quickly, AM fungi dominate. These fungi form smaller webs and do less intertree swapping, meaning the tropical wood wide web is likely more localized.
Ecologist Thomas Crowther’s results suggest that as the planet warms, about 10% of EM-associated trees could be replaced by AM-associated trees. Microbes in forests dominated by AM fungi deal with carbon-containing organic matter faster, so they could liberate lots of heat-trapping carbon dioxide quickly, potentially accelerating a climate change process that is already happening at a frightening pace.
1. What do we know about Suzanne Simard?| A．She was a professor and a forest detective. |
| B．Growing up in the countryside, she made the cover of Nature. |
| C．Like many other scientists, she made big influence on her PhD thesis. |
| D．Her idea of the “wood wide web” used to challenge people’s thoughts. |
| A．They facilitate tree communication. | B．They form an underground network. |
| C．They produce sugar and share it with trees. | D．They share nutrients and water with the trees. |
| A．They release warning signals through leaves. |
| B．They produce real bug repellent to kill insects. |
| C．They make use of hyphae to produce chemicals. |
| D．They send chemical signals through the network. |
| A．It might slow down carbon release. | B．It would break down organic matter. |
| C．It might speed up climate change. | D．It might lead to faster tree growth. |
2 . In times of intense stress, people sometimes let it out with a scream and a new study suggests that plants might do the same. Researchers at Tel Aviv University in Israel has found that plants let out ultrasonic (超声的) screams when damaged or stressed by drought.
The noises, falling within a range of 20 to 100 kilohertz, are too high-frequency for humans to hear, but other plants and some animals perceive them. Insects might be listening for sounds from stressed plants to assess their condition before laying eggs on their leaves. A moth (蛾) may decide against laying eggs on a plant that sounds water-stressed.
Researchers attached recording devices directly to plants to listen for secret sounds inside their stems (茎). In drought, air bubbles formed, burst and caused vibrations (振动) within the tissue that normally carries water up the plants’ stems. The process was picked up by the attached recording devices, but researchers wanted to know if any plant sounds could travel through the air.
So the team placed microphones 10 centimetres from stressed-out tomato and tobacco plants. They subjected one set of crops to drought and another to physical damage. A third group was untouched.
The microphones did pick up distinct sounds. On average, drought-stressed tomato plants let out about 35 ultrasonic screams per hour, while those with cut stems made about 25. Drought-stressed tobacco plants let out about 11 screams per hour, and cut crops made about 15 sounds in the same time. The average number of sounds from untouched plants fell below one per hour.
The researchers also attempted to identify each plant group just based on its screams. Using a type of artificial intelligence calculations, the team picked out distinct features in each set of sounds and successfully sorted their plants into three kinds: “dry, cut or untouched.”
If it is not too costly to set up the recording in a field situation, farmers might be able to hear these stress signals too. In future, enabling farmers to listen for water-stressed plants could “open a new direction”, which will be increasingly important as climate change exposes more areas to drought.
1. The moth is mentioned in paragraph 2 to show __________.| A．moths need enough water when laying eggs |
| B．some animals are able to hear plants scream |
| C．some insects are picky about their surroundings |
| D．wildlife species depend on each other when stressed |
| A．Plants’ sounds couldn’t be detected by humans. |
| B．Plants can be grouped according to their features. |
| C．Plants’ screams are related to stress types in a way. |
| D．Air bubbles contribute to the lack of water in plants. |
| A．Supporting evidence for the research result. |
| B．Potential application of the research findings. |
| C．A further explanation of the research methods. |
| D．A reasonable doubt about the research process. |
| A．Plants’ Vibrations: Way to React to Stress |
| B．Stress Signals: Secret Newly Found in Plants |
| C．Green Screams: Plants Make Noises When Stressed |
| D．Ultrasonic Screams: Discovery Opens a New Chapter |
3 . Many green plants that are used to decorate living rooms and kitchens are marketed as air-purifying. However, scientists largely agree that plants can’t do very much to clean an entire room. Now, a Parisian company known as Neoplants is trying to change that by growing genetically modified (转基因的) plants that help remove harmful chemicals from the air.
Its first product, called the Neo P1, is a bioengineered version of the pothos (绿萝). Pothos is characterized by its green leaves and is relatively easy to care for. The Neo P1 is meant to capture and recycle dangerous air pollutants commonly found in homes called volatile organic compounds (挥发性有机化合物VOCs), which are often human-made chemicals. So it’s a popular choice for people looking to beautify their living spaces. But the Neo P1 starts at $179, and to purchase one, potential shoppers must first join a waitlist.
The idea of air-purifying plants came from a 1989 study by NASA, in which regular houseplants were tested in two-by-two-foot rooms. When scientists filled these rooms with VOCs, they found the plants could absorb some of the harmful compounds. “Actually, it’d take about ten houseplants per square foot to noticeably improve air quality,” Michael Waring, an environmental engineer at Drexel University who wasn’t involved with Neoplants, reported in a 2019 study. “Plants, though they do remove VOCs, remove them at such a slow rate that they can’t compete with the air exchange mechanisms already happening in buildings,” Waring said.
As for Neoplants, its Neo Pl was tested in a 35-liter glass room. In it, the Neo P1’s results were 30 times better than NASA’s, according to the company — which means it’d still take a large number of them to clean a room. Currently, the company’s engineers are designing testing sites that more accurately resemble living spaces. To Neoplants’ executives, cleaning the air inside a home is a more logical starting point than trying to filter (过滤) the entire atmosphere.
1. What might prevent the Neo P1 from becoming popular?| A．Its poor quality. | B．Its unstable security. |
| C．Its high maintenance (维护，保养). | D．Its difficult availability. |
| A．Plants can significantly improve air quality in a room. |
| B．Plants contribute little to removing harmful chemicals. |
| C．The Neo P1 plays a big role in removing harmful compounds. |
| D．Houseplants are expected to replace air exchange mechanisms. |
| A．Exploring new ways to genetically modify plants. |
| B．Proving the Neo P1’s effectiveness in a living room. |
| C．Improving the air exchange mechanisms in buildings. |
| D．Designing testing sites that are similar to living spaces. |
| A．How do plants reduce air pollution? | B．What is the best plant to help clean the air? |
| C．Could genetically modified plants clean the air? | D．How can we decorate living rooms with plants? |
4 . Within the environmental movement, the question often arises whether global warming can be mitigated (缓解) by planting more vegetation. The idea is that the plants will consume carbon dioxide (CO2) that is causing the warming, while producing oxygen for us to breathe. This is acceptable on condition that global warming is indeed caused in some way by CO2 in the air.
However, actual scientific debate on the issue has shifted away from CO2 as the probable cause, especially after the findings that the temperatures changed 800 to 1000 years before carbon dioxide changed. In other words, CO2 levels are an indicator of temperature change, not a cause.
While there is nothing we can do to control the global climate, there is still a lot we can do to improve our local climates. Land use is the biggest decisive factor of local temperature and air quality. On clear days, the temperatures in big cities can be 5.6 degrees Centigrade higher than in the countryside around them. This is because the concrete (混凝土) of sidewalks and buildings and the asphalt (沥青) of roads take in sunlight and transform it into heat. Some get so hot, one could cook an egg on them! These vast surfaces of man﹣made stone also store lots of heat, which they radiate (散发) all night long. Just before sunrise, when the earth should be its coolest, roadways are still warm to touch.
If vegetation was blocking the Sun from the sidewalks and roads, the vegetation would absorb the sunlight, fueling the plants’ oxygen-making engines, and the rock would stay at surrounding temperatures. The easiest and most obvious choice is trees, particularly wide-reaching trees like the oak. Another possibility, especially outside the city centre, could be vine-covered trellises (棚架).Covering rooftops with grasses or other short vegetation reduces a building’s cooling cost as sharply as having trees or trellises that provide shade for windows does.
The reason why vegetation does not warm the air like rock does is that plants take water from the ground and evaporate (蒸发) it through their leaves. The Sun’s energy isn’t radiated as heat — it is used to change water into water vapor. The evaporative cooling works so well that the leaves stay 5.6 to 8.33 degrees Centigrade cooler than they would have been without water. While we can’t improve global climate, increased vegetation can help cool local climates.
1. Which of the following is True according to the passage?| A．With some effort, we can still affect global climate. |
| B．We can do a lot to improve the climate where we live. |
| C．Temperatures in big cities are usually lower than in the countryside. |
| D．The asphalt of roads throws back sunlight. |
| A．Planting full and wide-reaching trees. |
| B．Using vehicles that get better gas mileage. |
| C．Using energy-saving equipment. |
| D．Constructing dark-colored roofs on new buildings. |
| A．Darker colors absorb more sunlight and transform it into heat. |
| B．More thick materials store heat and give off it at night. |
| C．Human activity is changing global climate. |
| D．Vegetation is neither dark nor thick; thus, it reduces localized heating. |
| A．Encourage the next generation to increase vegetation. |
| B．Promote rooftop gardening. |
| C．Remove vines and trellises from buildings. |
| D．A and B above. |
5 . This is the time of year when many gardeners are harvesting tomatoes. Gardening expert Jessica Damiano recently reported about the many pictures of strangely shaped tomatoes sent to her from fans of her gardening advice.
Not every tomato on an affected plant will be deformed (改变形状), however. What are the possibilities? Under the right conditions (temperatures that are too hot or even too cold), this could affect one or two tomatoes per plant, depending on where they are in the development process and what the (weather) conditions are, said Timothy McDermott, a professor at Ohio State University. The possibility of one of your tomatoes developing a locule oddity (怪异) is about one in a thousand, McDermott said.
And, when harvesting your crop, remember:
| A．select the good-looking ones. |
| B．Any tomato can grow an extra locule. |
| C．the funny-looking tomatoes taste just as good! |
| D．What causes the unusual appearance of tomatoes? |
| E．Unless otherwise diseased, they are perfectly good for eating. |
| F．She said people sometimes question if the tomatoes are okay to eat. |
| G．Provide shade for your plants when temperatures are predicted to remain above 32℃. |
6 . When gardeners grow varieties of plants in their beautiful gardens, they are happy to see beneficial insects like bees and butterflies surrounding the flowers. But as they take a closer look, they may find some plants are covered in black dots and filled with harmful insects or pests. Some gardeners may immediately reach for chemicals.
If you are wise gardeners, you should first take preventive measures to control the harmful insects.
Prevention
As a rule, prevention is the best treatment. Inspect plants closely, including their leaves, before buying them from the store.
When planting, space plants out to permit them to grow to their full size. Plants too close together can breed harmful organisms, like bacteria.
Pesticides
If you decide a pesticide is necessary, choose it carefully and follow the directions and warnings on the product. Avoid using pesticides in extreme heat, on windy days, or when the plants are wet.
| A．But this is not wise. |
| B．In most cases, chemicals don’t help. |
| C．Treat the plants early in the morning or at night. |
| D．Also do remember the plants need nutrition and care. |
| E．Keep your garden free of fallen leaves, fruits and other wastes. |
| F．Do not bring any plants home that show signs of disease or pests. |
| G．The process starts with the idea that having some pests is acceptable. |
7 . “Consumers complain that the modern tomato has little flavor. It’s like a water bomb,” said Sanwen Huang, who works at the Agricultural Genomics Institute at Shenzhen at the Chinese Academy of Agricultural Sciences. “Tomato farmers care about yield, and the genetic variants related to yield are not related to tasty tomato favors.”
How can farmers ditch this unpleasant thing and recover the rich, sweet flavor of the tomato? To find out, Huang and colleagues investigated which genes are related to tomatoes’ taste. The scientists created a 100-person group that sampled 160 tomatoes based on sensory qualities. Based on the group’s feedback, the researchers identified dozens of chemical compounds (化合物) that could be related to the tomato’s taste. Using a statistical model that determined the concentration of various chemicals in the tomatoes, the scientists identified 33 most important flavor compounds. The researchers then measured the content of them in each of the tomatoes, and identified about 250 genetic loci (基因座) that controlled tomato flavor. This finding revealed the genetic basis of tomato flavor.
But the researchers also wanted to determine why store-bought tomatoes don’t taste good. It turns out that modern tomato varieties are selected according to qualities such as big size because buyers prefer large fruit, and firmness because it makes tomatoes easier to ship. Meanwhile, the quality of flavor has been ignored, said the researchers.
Volatiles (挥发性物质), in particular, are essential for good flavor. The removal of specific volatiles from tomatoes results in significant reduction in people’s liking. Moreover, refrigeration can change a tomato’s volatile compounds.
“But there is hope for a future filled with tasty, new varieties of store-bought tomatoes, as our results provide a road map for improvement of flavor. By working together, geneticists, biochemists, farmers and customers can provide better-flavored tomatoes for our society.” Huang said.
1. How does the author present the study in paragraph 2?| A．By giving a definition. | B．By listing figures. |
| C．By analyzing the cause. | D．By making a comparison. |
| A．The reasons why stores favor such tomatoes. |
| B．Some qualities consumers prefer in buying tomatoes. |
| C．The importance of volatiles in deciding tomato flavor. |
| D．The reasons why store-bought tomatoes have little flavor. |
| A．The store-bought tomatoes have a promising future. |
| B．Yield-related genetic variants provide tasty tomatoes. |
| C．Their research has changed a tomato’s volatile compounds. |
| D．Farmers and customers can certainly provide better-flavored tomatoes. |
| A．To persuade readers to buy tomatoes. |
| B．To introduce the high yielding tomatoes. |
| C．To prove store-bought tomatoes are tasteless. |
| D．To inform readers of the research about tomato flavors. |
8 . “A beautiful field of flowers can be a rather noisy place. It’s just that we can’t hear the sounds.” Scientists at Tel Aviv University have conducted a six-year experiment, proving that plants make noise in certain stressful situations.
Plants produce a high frequency (频率) clicking sound, and when short of water, or damaged, the clicks become far more regular. They also made different sounds, depending on whether they were thirsty or injured. “Each plant and each type of stress is related to a specific sound,” said Professor Lilach Hadany, who led the research study.
Focusing particularly on tomatoes, wheat and corn, the plants were placed in a soundproof(隔音的)room and recorded by microphones. Some plants were starved of water, others cut, and a control group was left undamaged. The researchers used an algorithm (算法) to separate the noises, suecessfully telling the difference between the sounds depending on whether they were dry or cut. The algorithm did this in a greenhouse setting which included far more surrounding sounds, but it was still able to recognize the particular cries for help of the plants.
On average, the human ear can hear sounds up to around 20kHz, while the sounds produced by plants are in the 40-80kHz region, far beyond our hearing. “The sounds made by plants can’t be heard by humans but can probably be heard by various animals, such as bats, mice and insects,” Hadany tells us. Though this has yet to be proven, it’s possible that these creatures use this information to choose which plants to eat.
A study led by Reda Hassanien of China Agriculural University in Beijing years ago, also proved that plants reacted to sound waves, with some plants greatly increasing their yield. While evidence shows that plants can react to sounds, there’s no evidence today that they can actually hear them.
1. What can we know from the six-year experiment?| A．Plants of different types make the sound of the same frequeney. |
| B．Plants produce more regular sound in certain stressful situations. |
| C．Plants make sounds with a much lower frequency when stressed. |
| D．Plants make the sound of the same frequeney whatever the situation. |
| A．To record the sounds. | B．To control the sounds. |
| C．To produce the sounds. | D．To identify the sounds. |
| A．Plants can hear each other’s cry for help. |
| B．Animals can hear the sounds made by plants. |
| C．Plants can make sounds and respond to sound waves. |
| D．Animals decide what to eat based on the sounds plants make. |
| A．Sounds That We Can’t Hear |
| B．Beautiful Songs from Plants |
| C．Plants React to Different Types of Stress |
| D．Plants Talk, Especially When Stressed |
9 . Trees naturally absorbed CO₂ through photosynthesis(光合作用), releasing oxygen, storing carbon for decades, or even centuries. Biotechnology firm Living Carbon says lab trials of its genetically-changed poplar trees take up more carbon and grow 1.5 times faster than unchanged ones. The team added genes from pumpkin to the poplars, which makes their photosynthesis more efficient, turning more carbon dioxide into sugars to create wood biomass(生物量).
Though the firm’s lab results are promising, biologists warn that high growth rates are not guaranteed in the wild as the poplars compete for sunlight with other plants and trees. Genetically-modified (GM)supertrees may also need much watering and fertilizer to keep their rapid growth.
The results are important given the rate of climate change and climbing CO₂ levels in the atmosphere. But critics say there are risks to planting GM trees in the wild if they reproduce with other trees, or negatively affect other plant and animal species. Living Carbon says trees are a hybrid that can only reproduce from cuttings, so cannot cross-pollinate(授粉) with wild trees.
If the field trials are successful then it will still take time to get approval from the government. One sixth, around 135, tree species in the US may face extinction due to climate change, foreign insect species, or disease. And even though field trials of a GM chestnut tree have shown its ability to resist some foreign disease that wiped out billions of American chestnuts, it still has not been approved for planting.
If CO₂ storage is the aim then there are species that already fit the bill. California’s Redwood trees store more carbon than any other species. Redwoods are not suitable for every forestry plot, so creating climate adaptable trees through reproducing programs that fit into local ecosystems is the goal. But in the rush to fix the climate crisis, increase CO₂ uptake, and carbon storage, GM supertrees may be part of that solution.
1. How was the poplars’ carbon capacity improved?| A．By absorbing carbon dioxide. | B．By producing wood biomass. |
| C．By speeding up photosynthesis. | D．By engineering their genes. |
| A．They reproduced with other plants. | B．It is impossible to get approval. |
| C．It is hard to grow fast in the wild. | D．They are not competitive enough. |
| A．Be unusual. | B．Be available. | C．Be unsuitable. | D．Be valuable. |
| A．Supertrees Could be Climate Fix. | B．Supertrees Take up More Carbon. |
| C．Change of Genes Reduce CO₂. | D．Changes of Genes Brings Efficiency. |
10 . Plants and exposure to greenery have been found to have mental health benefits and like any new skill or hobby, taking care of houseplants comes with difficulty. Anyone starting to care for plants should be patient and allow themselves time to learn the basics. Here are several plants recommended for giving mental health benefits:
Snake Plant
These popular indoor plants have a striking appearance, with dark green sword-shaped leaves that have yellow or white stripes. It is a great first plant, and is very easy to care for. It grows in spaces with low sunlight, has visual appeal and cleans the air.
Lavender
Well known for its relaxing smell, lavender has a calming effect, aids in reducing stress, promotes sleep and specially has anti-inflammatory (抗炎的) effects when used as a medicine for skin. You can cut it off and dry the leaves or even put them into your bath.
Pothos
If you want to go bright green, try pothos. The plants grow long stems that can hang from a pot and grow downward, or the stems can climb and grow upward. They clean the air and look beautiful hanging down a bookcase or shelf.
Lemon Balm
This fragrant green herb is part of the mint family and is simple to plant. Known for its calming properties, it has a light lemony smell and has been used to improve sleep, reduce stress and anxiety.
Basil
The experience of growing, picking and using herbs you’ve grown yourself has a positive impact on your mental health, creating a sense of accomplishment. Eating basil has health benefits too. It has properties that help to relieve stress and anxiety, and eating it can clear your mind.
1. What do snake plant and pothos have in common?| A．Long stems. | B．Bright green leaves. |
| C．Purifying the air. | D．Relaxing your mind. |
| A．Promoting sleep. | B．Resisting inflammation. |
| C．Reducing stress. | D．Clearing your mind. |
| A．Basil. | B．Snake Plants. | C．Pothos. | D．Lavender. |
