Nature’s Lungs
We know that trees are nature’s purifier (净化器): They absorb carbon emissions (碳排放)and release oxygen. But their
According to the study, there are
This may sound like a lot,
Yet, planting trees is still considered the most effective way
2 . 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. |
3 . 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 |
Stretching along the west coast of North America from northern California to Alaska, the forests found along the Pacific Coast Range are the largest area of temperate (温带的) rainforest in the world. The forests are home to the coast redwood, the world’s tallest tree. Across the region, the forest understory (林下叶层) is wet and heavily vegetated.
Taiheiyo Evergreen Forests
Found in southern Japan, they are temperate rainforests of evergreen broadleaf trees. The forests can receive more than 100 inches of rain every year. The forests are covered by Japanese cedar and Japanese stone oak, while moso bamboo comprise the understory. The extent of the Taiheiyo forests has been reduced due to development and agriculture. Today,17%of the remaining forest is protected by national parks and other reserves.
Atlantic Oakwood Forest
The Atlantic Oakwood Forest covers the wettest parts of the United Kingdom. A species of oak tree (橡树) called sessile oak occupies the landscape. Unlike other temperate forests, these forests tend to have an open understory of grasses. Much of the historical range of the forest has given to agriculture and other development, though that has changed in recent decades.
Valdivian Temperate Rainforest
This forest is found on the west coast of Chile and Argentina, on the wet, western slopes (斜坡) of the Andes mountain range. With the coastline to the west, the peaks of the Andes to the east, and the Atacama Desert to the north, the region supports a number of plant and animal species found nowhere else in the world. Uniquely, the forest is covered by evergreen flowering trees, which are native to Chile and little known outside the region.
1. Which of the four forest areas occupies the most land?| A．Pacific Coast Range. | B．Taiheiyo Evergreen Forests. |
| C．Atlantic Oakwood Forest. | D．Valdivian Temperate Rainforest. |
| A．They have open understory grasses. | B．They’re home to extremely tall trees. |
| C．They’re of great historical significance. | D．They used to be affected by agriculture. |
| A．Wet climate. | B．Coastal location. |
| C．Evergreen flowering trees. | D．Well-protected national parks. |
5 . Emmanuel Mendoza, a college student, is currently running a study at Texas A&M University, where he’s mixing simulated (模拟的)Martian (火星的) soil and frass(粪便)from fly larvae(幼虫)to find just the right recipe for growing plants on Mars.
The seed of this idea was planted when Mendoza was in middle school, watching Ridley Scott’s 2015 film The Martian, in which Mark Watney becomes stuck on the planet and grows potatoes to survive. “That got me really interested in what nutrients or what soil structure Martian soil has that we could potentially take advantage of, ”Mendoza said.
Now, he’s running an experiment growing English peas in simulated Martian soil. “I definitely considered potatoes like Mark Watney, ”he said. “But the fact was that I couldn’t necessarily get the data I wanted out of them. ”
He wanted to be able to measure plant growth as it occurred throughout his experiment. Since potatoes grow underground, he’d only be able to collect data once they were done growing. In the end, Mendoza chose to grow English peas because they’re self-pollinating(自花传粉), grow fairly quickly and he can see the shoots climb.
Martian soil, though it does contain other essential nutrients, isn’t exactly ideal for plants from Earth. It tends to be rocky and lacks the right organic (有机 的)matter. Here’s where the larvae come in. Mendoza turned to the larvae of black soldier flies, which produce a waste known as frass. “They can break down almost any biomatter and turn it into really useful matter, “Mendoza said. “And then you can use the frass as a nutrient alternative to soil.”
For this experiment, Mendoza mixed different percentages of simulated Martian soil and frass to see what best supported growing English pea plants. Now, he said he’s seeing growth across all his plants—even the ones growing in 100%simulated Martian soil.
1. Why does the author mention the film The Martian?| A．To show Mendoza’s enthusiasm for films. |
| B．To illustrate Mark Watney’s intelligence. |
| C．To prove Mark Watney’s interest in gardening. |
| D．To introduce the origin of Mendoza’s experiment. |
| A．He was unwilling to repeat others’ study. |
| B．English peas grew far faster than potatoes . |
| C．Potatoes needed stricter living conditions. |
| D．It was more convenient to collect the data. |
| A．It serves as certain essential nutrients. |
| B．It loosens the soil for plants to grow. |
| C．It makes the soil become quite rocky. |
| D．It helps black soldier flies grow stronger. |
| A．Doubtful. | B．Pleased. | C．Intolerant. | D．Disappointed. |
6 . Growing plants at home is a fun and enjoyable activity to do and can be developed as a new hobby.
Gardening reduces stress. Gardening is one of the most effective, and fun ways to free yourself from the physical, mental, and emotional stress you have been carrying since the beginning of the week. If you are overworking yourself during the weekdays or seeing yourself drowning in stressful thoughts, try to spend your weekends gardening at home.
Gardening is good for your heart. Gardening requires our body to move around by doing simple tasks such as digging the ground, planting seeds, pulling out weeds, and carrying a water container’s load.
By spending our free time gardening and monitoring our plants’ growth, we are also taking care of ourselves as we gain lots of health and emotional benefits. It is a worthwhile activity because we get to see the results of our hard work when our plants start growing fonder and healthier. The way we take care of our plants reflects the way we take care of ourselves.
| A．Gardening is an act of self-love. |
| B．Gardening is good for your bones. |
| C．Gardening helps your body against diseases. |
| D．You will see a significant change in your mind. |
| E．These simple gardening tasks can be considered a low-level exercise. |
| F．It also has several positive health and emotional benefits that you can enjoy. |
| G．Returning home to a place full of beautiful plants helps us enjoy the freshness of the air. |
7 . 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? |
From “pocket parks” between communities to forest parks in the outer cities, local governments are
From 2021 to 2022, Shanghai transformed 62 woodlands into leisure spaces. These leisure spaces open up forests,
Apart from meeting people’s needs, parks can also do good to the environment. Take Beijing’s Central Green Forest Park
9 . Scientists have known for years that plants respond to sounds around them. For example, flowers make sweeter nectar (花蜜) to the sound of buzzing bees. But now scientists in Israel have shown that plants also seem to be doing some “talking”.
Professor Lilach Hadany and her team at Tel Aviv University set up microphones to record tomato and tobacco plants under different conditions. Their recordings showed that the plants made ultrasonic (超声波的) sounds.
When the researchers adjusted their recordings so that humans could hear them, they heard sharp clicking noises. Plants clicked hardly at all when they had enough water. But as their soil got drier, they clicked more and more. When scientists cut off a stem (茎) from the plants, the plants also clicked more. But the clicking wasn’t the same as when the plants needed water.
It’s not clear how the plants make the sounds and whether the plants are making the sounds on purpose. But the plants are definitely making noises, and creating much more noises when they’re stressed (not enough water, stem cut off) than when they’re not.
The researchers trained an Artificial Intelligence (AI) system to identify the different kinds of clicking sounds. The system was able to tell the difference between plants that needed water and plants with cuts about 70% of the time. The result suggests that researchers may one day be able to use a plant’s sounds to figure out when it is having trouble, and what trouble it is having. That could be very helpful to farmers.
The new discovery raises many more questions. One important question is: Do plants make sounds to communicate with each other? Other research has shown that plants do seem to communicate in some ways. Plants being attacked by insects send chemicals into the air. Soon, nearby plants (that haven’t been attacked yet) start to make other chemicals that don’t taste good to insects. It’s possible that the ultrasonic sounds could work in a similar way.
1. What do the researchers find in their recordings?| A．Plants’ stems click less when they are cut off. |
| B．Plants click harder if they have enough water. |
| C．Plants make more noises when they are thirsty. |
| D．Flowers make sweeter nectar to the sound of bees. |
| A．There are still some unknown issues. |
| B．Not all of them are able to make sounds. |
| C．There are ultrasonic sounds around them. |
| D．They make less noises when they’re stressed. |
| A．To help farmers drive away insects. |
| B．To identify people who are in trouble. |
| C．To show the growing process of plants. |
| D．To distinguish types of clicking sounds. |
| A．Methods for plants to protect themselves. |
| B．Other questions raised by the new finding. |
| C．When plants communicate with each other. |
| D．Under what conditions plants attract insects. |
10 . The world loves a cup of tea. It only takes a few grams to make a cup of tea and millions of tons of tea are consumed every year. Tea can be good for you because it contains some things that help lower cholesterol and reduce the risk of cardiovascular disease. Tea also contains caffeine(咖啡因), which improves not only mental alertness but can also increase anxiety and cause other problems.
What would be agreeable is a tea plant that provides all the taste and goodness but with little or none of caffeine. Chen Liang and Jin Jiqiang in the Tea Research Institute, Chinese Academy of Agricultural Sciences think they have found just such a plant, growing wild in a remote area in southern China’s Fujian Province. Known locally as hongyacha, the discovered plant grows only between 700 meters and 1,000 meters above sea level around a handful of Chinese villages. As they report in the Journal of Agricultural and Food Chemistry, not only is the tea plant naturally caffeine-free but it also contains a number of unique medicinal compounds that, the locals believe, offer considerable health benefits.
The researchers are now exploring methods to protect hongyacha in its natural habitat while further studies are carried out. It can take time—and sometimes it does not work—for new plant varieties to be bred for commercial use. A pair of naturally caffeine-free coffee plants were discovered in 2003, but little progress has been reported. Tea lovers will be watching hongyacha with interest. And others will wonder what else is out there.
1. What’s the disadvantage of drinking tea according to paragraph 1?| A．It can make people hard to sleep. | B．It can make people feel anxious. |
| C．It can get people addicted. | D．It can take people much time. |
| A．It is nothing but just medicine. | B．It can only survive in greenhouses. |
| C．It is a good pick for caffeine lovers. | D．It has a good taste and little caffeine. |
| A．Its future location. | B．Its natural habitats. |
| C．Its future market. | D．Its production process. |
| A．A health magazine. | B．An advertising brochure. |
| C．A travel guidebook. | D．A newspaper. |
