A study published recently shows that tomato fruits are able to transmit alerts to their mother plant when attacked by caterpillars.
Plants have a large number of chemical and hormonal signaling pathways, which are generally transmitted through the sap (树液). Given the fact that fruits just hang from the main plant before ultimately falling off and sap typically only runs from the plant to the fruit — not back and forth between the two — it has long been unclear whether or not fruits can transmit information to the plant.
To address that question, scientists at Brazil’s Federal University of Pelotas placed tomato plants in a Faraday cage. Electrodes (电极) were attached to the ends of the plants’ branches at the points where they connected to the fruits. Then they measured electrical responses within the branches before, during and after a 24-hour period in which the fruits were attacked by caterpillars. Machine-learning-based algorithms were used to identify patterns in the signals.
It was found that there was a “clear difference” between the signals before and after caterpillar attacks. Additionally. defensive biochemical responses were observed throughout the plants’ bodies, suggesting that they had been triggered by signals sent by the fruits. There searchers gave the following explanation. The tomato fruit, sensing a nearby insect, released electrical signals to reach the rest of the plant. These warnings impulses were received by the main plant and as a result, the rest of the plant got prepared to fight off the unwanted invaders. The tomato fruit made sure that the plant produced chemicals that were unpleasant to taste, so that hungry caterpillars stayed off the fruit.
The scientists now plan on investigating whether other fruiting plants behave in the same manner as tomatoes, and whether their fruits respond to threats other than insects. They believe understanding how the plant interacts with its fruits, and the fruits among themselves, may bring insights into how to make use of this communication for enhancing fruit quality, resistance to pests and shelf life after harvest.
1. Which of the following magazine is the text most likely selected from?| A．Frontiers in Sustainable Food Systems. |
| B．Extraordinary Architect. |
| C．National Geographic. |
| D．The Economist. |
| A．A medium that can transmit signals. |
| B．A firewall that can prevent attacks. |
| C．A shelter where information stores. |
| D．A pathway which water runs through. |
| A．It fought against the invaders. |
| B．It produced an unpleasant taste. |
| C．It released a stinky smell. |
| D．It emitted electrical signals. |
| A．Improve fruit output. |
| B．Decrease pest species. |
| C．Expand research fields. |
| D．Investigate other insects. |
相似题推荐
【推荐1】If you’re studying English or another foreign language, you might be wondering. “How is this going to help me in my life?” As it turns out, studying and thinking in a foreign language has its own benefits!
In a 2012 study, Boaz Keysar, a professor at the University of Chicago in the US, led an experiment concerning the relationship between foreign languages and people’s way of thinking. In the experiment, people were asked to make a choice: Take a guarantee of one pound or take a 50 percent chance of winning 2.50 pounds. When presented with this choice in their native language, most people took the safe option of only getting one pound. But they were more willing to make the riskier choice when asked in a foreign language, leading to more profits overall.
In another study published this year, Keysar and his team did an experiment in which participants were given a series of related words like “dream”, “snooze (打盹)”, “bed” and “rest”. Later, when asked which words they remembered hearing, people were more likely to mistakenly remember “sleep”, which was not on the list, in their native language. But it was much less likely to happen if they did the test in a foreign language. As Keysar explained, people have more careful thinking when using a foreign language, leading to memories with greater accuracy.
The foreign language effect may even stretch to our personality. Silvia Purpuri at the University of Trento, Italy, looked at people’s willingness to face uncertainty and enter unfamiliar situations. Being tolerant of uncertainty allows people to have more creative ideas and be more open to new things. It turns out that people naturally score more highly on this trait (特点) when they can speak or use a foreign language because speaking a foreign language requires taking risks. The evidence is clear: By learning a foreign language, you’re not just learning a language-you’re gaining a new state of mind.
1. In Keysar’s experiment, when making decisions in a foreign language, people tend to be ______.| A．decisive | B．hopeful | C．daring | D．careful |
| A．It improves memory accuracy. |
| B．It increases memory recall speed. |
| C．It strengthens long-term memory. |
| D．It requires repeated memorization. |
| A．Increased creativity. | B．Greater tolerance. |
| C．Better learning ability. | D．Boosted adventurous spirit. |
| A．Challenges of learning a foreign language. |
| B．Advantages of learning a foreign language. |
| C．How foreign language learning influences memory. |
| D．How foreign language learning determines one’s future. |
【推荐2】“While animals can’t pick out precise numbers, they can understand that more is more. Interestingly, we know now that numerical competence is present on almost every branch of the animal tree of life,” says Andreas Nieder, a neurobiologist from the University of Tuebingen. “Different groups of animals obviously developed this competence independently from others and that strongly indicates that it has to be of adaptive value.”
Honeybees, for instance, can remember the number of landmarks they pass when searching for food in order to find their way back to the hive. The last common ancestor between honeybees and primates lived about 600 million years ago. But still, they evolved numerical competence that, in many respects, is comparable to vertebrate numerical competence. Also, for example, male frogs sing “advertisement” calls to attract females. The females, listening for the complexity of their calls, choose the male that sings the most calls.
Wolves are more likely to hunt successfully if they have the right number of wolves in their pack for the size of their prey: With prey like deer, only around six to eight wolves are needed, while hunting wild ox requires a pack of nine to thirteen. Their prey also uses this concept to protect themselves from predators — deer tend to live in large herds to reduce the chance of any individual becoming prey. So obviously they are assessing the number of individuals in their groups for their everyday life situations.
Despite these many examples of numerical competence in animals, this subject has not gotten many first-hand studies. “Many of these behavioral findings in the wild have usually been collected as by-products or accidental findings of other research questions,” says Nieder. He argues that more research needs to be done to fully understand the numerical competence.
1. The phenomenon of animals having their own numerical competence shows that ________.| A．all groups of animals can know the exact numbers |
| B．numerical competence must have a survival benefit |
| C．animals’ intelligence varies with different environments |
| D．animals’ numerical competence is determined by their independence |
| A．It helps them form proper hunting groups. | B．It gives them more options to hunt. |
| C．It makes them discover more prey. | D．It offers them new skills to hunt. |
| A．By listing figures. | B．By asking questions. |
| C．By giving examples. | D．By making comparisons. |
| A．A biology textbook. | B．A health magazine. |
| C．A travel brochure. | D．A science report. |
【推荐3】Like many of my generation, I have a weakness for hero worship. At some point, however, we all begin to question our heroes and our need for them. This leads us to ask: What is a hero?
Despite immense differences in cultures, heroes around the world generally share a number of characteristic that instruct and inspire people. A hero does something worth talking about. A hero has a story of adventure to tell and a community who will listen. But a hero goes beyond mere fame.
Heroes serve powers or principles larger than themselves. Like high-voltage(电压) transformers, heroes take the energy of higher powers and step it down so that it can be used by ordinary people.
The hero lives a life worthy of imitation. Those who imitate a genuine hero experience life with new depth, enthusiasm, and meaning. A sure test for would-be heroes is what or whom do they serve? What are they willing to live and die for? If the answer or evidence suggests they serve only their own fame, they may be famous persons but not heroes. Madonna and Michael Jackson are famous, but who would claim that their fans find life more abundant?
Heroes are catalysts(催化剂) for change. They have a vision from the mountain top. They have the skill and the charm to move the masses. They create new possibilities. Without Gandhi, India might still be part of the British Empire. Without Rosa Parks and Martin Luther King, Jr, we might still have segregated(隔离的) buses, restaurants, and parks. It may be possible for large-scale change to occur without leaders with magnetic personalities, but the pace of change would be slow, the vision uncertain and the committee meetings endless.
1. Although heroes may come from different cultures, they .| A．generally possess certain inspiring characteristics |
| B．probably share some weaknesses of ordinary people |
| C．are often influenced by previous generations |
| D．all unknowingly attract a large number of fans |
| A．they have a vision from the mountaintop |
| B．they have warm feelings and emotions |
| C．they can serve as empowering examples of noble principles |
| D．they can make all people feel stronger and more confident |
| A．they are popular only among certain groups of people |
| B．their performances do not improve their fans morally |
| C．their primary concern is their own financial interests |
| D．they are not clear about the principles they should follow |
| A．are good at demonstrating their charming characters |
| B．can move the masses with the skill and the charm |
| C．are capable of meeting all challenges and hardships |
| D．can provide an answer to the problems of their people |
| A．be delayed without leaders with inspiring personal qualities |
| B．not happen without heroes making the necessary sacrifices |
| C．take place if there were heroes to lead the people |
| D．produce leaders with attractive personalities |
【推荐1】A lot of manufactured glass today made from sand and sodium carbonate (碳酸钠) can be reused or melted down and recycled into new items, but it doesn’t break down in the environment and will sit in landfills for thousands of years. A team of Chinese scientists aimed to deal with this environmental concern by developing an eco-conscious alternative.
In a study published recently in the journal Science Advances, a team at the Chinese Academy of Sciences’ Institute of Process Engineering describe how they engineered biodegradable glass made from amino acids (氨基酸). That glass would have a smaller impact on the environment and can break down in a few weeks or in several months.
In a test, glass beads made out of amino acids were placed under the skin of mice, and the breakdown of the bead and the skin healing process were observed for 30 days. A diagram from the study shows how the mice’s bodies broke down the beads. In that month, the glass implant degraded beneath the skin, the wound site healed, and fur grew back. “Throughout the experimental period, no mice exhibited any pain-related behavior that may have been caused by the glass implantation, and none of them experienced obvious weight loss,” the researchers wrote in their paper.
Although amino acids do degrade over time in the environment, this biodegradable glass is not as durable as traditional glass, because amino acids can break down quickly in heat. To overcome this problem, the researchers chemically modified amino acids using the heating-cooling process tailored for manufacturing the new glass. This is when materials for the glass are heated to become soft and then rapidly cooled so as to make the glass tougher.
“It’s important to point out that this biodegradable glass is currently in the lab stage, and far from large-scale commercialization,” emphasized Yan Xuehai, a professor involved in the study, in a press release.
1. What has been found after researchers implanted glass beads inside mice?| A．The gradual degradation of the beads. | B．The recycling process of the beads. |
| C．Swollen wound sites of the mice. | D．Apparent weight losses of the mice. |
| A．The enhanced durability through chemical adjustment. |
| B．The adoption of traditional glass manufacturing procedures. |
| C．The prolonged exposure to heat during glass production. |
| D．The rapid degradation of amino acids in the environment. |
| A．Disapproving. | B．Objective. |
| C．Ambiguous. | D．Dismissive. |
| A．Amino acids make eco-friendly glass durable. |
| B．Biodegradable glass gains popularity in the market. |
| C．Biodegradable glass offers a solution to ecological sustainability. |
| D．Amino acids provide inspiration in glass manufacturing. |
【推荐2】If you spend more than a couple of days in the country of Georgia, you are very likely to be invited to a Georgian feast even by complete strangers. The multi-hour, multi-course feast is one of the most important events in Georgian culture.
A popular Georgian story shows the importance of the feast in Georgian culture. When God created the world, He held a meeting to give the different regions of the world to different cultures. But the Georgians arrived late at the meeting. After they apologized and explained that they’d been holding a feast with a stranger the night before and slept later than they’d meant to, God was so touched and impressed by their honesty that He gave the Georgians the best land of all: the part of earth He was saving for himself.
In order to survive the feasts without offending (冒犯) the hosts, it’s important for you to know a few things about it in advance.
A Georgian feast will likely have a seemingly unlimited number of dishes. So avoid fully cleaning your plate unless you want more servings. Don’t fill up on khachapuri-Georgian cheese bread. There are numerous regional varieties of cheese bread, but khachapuri is the most delicious of all. The cheese bread is usually a heavy lunch on its own, but at feasts it’s often considered a side dish or an appetent. Don’t make the mistake of having more than a few bites—only to discover that the main meal is still coming.
When you drink, follow the lead of the toastmaster, who presents a scries of toasts throughout the evening. Traditionally, drinkers would dry their glass (or, if keeping with tradition, drain their deer’s horn) with every toast. This isn’t always done now. Just remember the important rule: say “cheers” after every toast.
Consider bringing a small gift, such as sweets or flowers, as a gesture of thanks. Avoid bringing more fond, however, which might imply that you don’t think there will be enough on offer.
1. What can be most probably inferred from the story?| A．Georgia is short of natural resources |
| B．Most of the Georgians are lazy and wasteful. |
| C．The Georgian people are very honest and friendly. |
| D．It is important to go to a meeting on time in Georgia. |
| A．It is not a main dish at feasts at all. |
| B．Georgians usually have it for breakfast. |
| C．It is one of the unique Georgian drinks. |
| D．Many regional varieties are based on it. |
| A．Drink all the wine every time. |
| B．Take some small gifts with them. |
| C．Clean the plate after each serving. |
| D．Bring some special food to the feast. |
| A．Amazing Food History in Georgia |
| B．Basic Rules of Being a Good Host |
| C．Bad Manners to Be Avoided at the Table |
| D．Things to Be Learned About Georgian Feasts |
【推荐3】The rapid growth in skyscrapers worldwide has led to a high demand for window washers since most of these buildings feature large glass panes (窗格) to highlight their breathtaking views.
Though the job offers a handsome salary, dangling alongside multi-story structures is dangerous, and accidents are not uncommon. However, if Israel-based company Skyline Technologieshas its way, the dangerous chore may soon be taken care of by Ozmo, an intelligent window cleaning robot.
"As a society, we've become too comfortable watching people hanging off the sides of 30-story buildings," says Yaron Schwarez, co-founder and CEO of Skyline Robotics. "No salary could justify allowing people to put their lives in the hands of a system of ropes."
Much like humans, Ozmo is placed on platforms suspended from the buildings and uses its arms and brushes to clean the dirt on the glass panes. A 3D map of the building's surface programmed into its system allows the robot to skillfully handle obstacles as it moves up and down the structure. Computer vision and touch sensors enable it to move out of the way in case of unexpected events, such as the sudden opening of a window.
Unlike current window washers, the robot cleaner does not require soap to clean the glass. Instead, it uses distilled water (蒸馏水) and a process called dirt absorption to do the job. Schwarez explains, "We use pure water to absorb and remove the salts, the minerals, the oils, and the dirt from the building. We are environmentally-friendly."
Ozmo is also expected to be much more efficient than humans. While it currently takes three cleaners 480 hours each to clean the windows of a 40-story glass building, the robot will single-handedly complete the task in just 80 hours. However, unlike other robots, Ozmo will not replace human workers. It will only make their jobs safer by lifting them to the role of supervisors, who will be remotely controlling the operation from below.
Whether Ozmo, which is still undergoing testing, does as good a job as human remains to be seen.
1. Which of the following can best replace the phrase "has its way" in paragraph 2?| A．Succeeds. | B．Hesitates. |
| C．Struggles. | D．Exists. |
| A．It requires chemicals to clean. |
| B．It has trouble crossing obstacles. |
| C．It operates with great efficiency. |
| D．It works without human helpers. |
| A．Optimistic. |
| B．Doubtful |
| C．Unconceded. |
| D．Objective. |
| A．Ozmo: a Double-edged Sword. |
| B．Ozmo: a Smart Window Cleaner. |
| C．Window Washing: a Dangerous Job. |
| D．Window Washing: a Blessing in Disguise. |
【推荐1】Off the coast of Formentera, an island, lives seagrass that stretches 15 kilometres. The seagrass, covering several hectares, is made up of a single organism. The grass is also long-lived, for tens or hundreds of thousands of years. Along with two other kinds of coastal ecosystems — mangrove swamps (红树沼泽) and tidal marshes, seagrass meadows are particularly good at taking carbon dioxide from the air.
This role was highlighted in a report, which was published on March 2nd by UNESCO, on blue carbon — the carbon taken in by Earth’s oceanic and coastal ecosystems. In total around 33 billion tons of carbon dioxide, about three quarters of the world’s emissions in 2019, are locked away in the planet’s blue carbon sinks. Research by Carlos Duarte, the report’s author and a marine (海洋的) ecologist, has shown that one hectare of seagrass can take in as much carbon dioxide each year as 15 hectares of rainforest.
One reason that blue-carbon ecosystems make such effective sinks is that underwater forests are thicker than the land-based woods. They can also trap (收集) floating pieces and organic matter, which settles on the sea floor and can double the amount of carbon stored away. They have another advantage, too. Climate change is leading to more wildfires around the world. As forests burn, their carbon stocks are released back into the atmosphere. Unlike forests on land, blue-carbon ecosystems do not burn.
Blue-carbon ecosystems may not be fired, but they remain affected to other sorts of disasters. In May 2020 hurricane Amphan destroyed 1,200 square kilometres of mangrove forest. A marine heatwave in Australian waters in 2010 and 2011 damaged around one third of the world’s largest seagrass meadow in Shark Bay. “Mangrove forests can weaken or control waves and provide natural barriers to storm surges. Protecting and expanding them, then, appears to be a must,” said a marine biologist.
1. What does the second paragraph mainly talk about?| A．The detailed explanation of blue carbon. |
| B．The special features of the seagrass. |
| C．The doubt about the blue-carbon ecosystems. |
| D．The capacity of the blue-carbon ecosystems to store carbon. |
| A．There are more underwater animals. |
| B．Their carbon stocks are released back. |
| C．They have great ability to absorb carbon. |
| D．They aren’t influenced by natural disasters |
| A．Humans should preserve blue-carbon ecosystens. |
| B．Mangrove forests can strengthen waves. |
| C．Mangrove forests are too strong to be broken. |
| D．Blue-carbon ecosystems can be fired. |
| A．Blue-Carbon Ecosystem Are Expanding Much Faster |
| B．The Grasses Can Store More Carbon Than Your Expectation |
| C．Mangrove Forests Can Control Waves Efficiently |
| D．Plants in the Ocean Are Better at Storing Carbon |
【推荐2】Ariel Novoplansky, an ecologist in Israel, set up an experiment among pea plants to study how they communicate with each other.
In the experiments Ariel put the pea plants in rows of containers. The center plant in the row was the target. The pea plants had been grown with two main roots. On one side, each pea plant had one root in its own pot and the other reaching into a neighbor’s pot. The central plant connected to its closest neighbor, which connected to another neighbor, and so on down the line. On the other side, all the plants kept their roots in their own pots, unconnected to their neighbors.
With everything ready, the ecologist created a dryness for the central target plant, which had quickly closed up its leaf pores (气孔) to save water. Amazingly, the connected plants on one side gradually closed up their leaf pores, even though only one of them had experienced real dryness. On the other side, with unconnected roots pea chain, all their pores stayed open. This means the warning signal didn’t travel from the stressed plants leaves through the air, but only from its roots through the soil.
It’s possible that plants are just eavesdropping (偷听) even if the damaged plant didn’t mean to send signals to them. Maybe the damaged plant leaks certain chemicals and nearby roots could sense those signals. But the plants with connected roots that weren’t dried out passed on the drought signals to their neighbors too, which means simple eavesdropping probably isn’t the answer. They seem to be having a real conversation, picking up information on one side and sharing it with a neighbor on the other.
The benefit to a plant that receives this information is pretty clear. But what’s the benefit to sending a danger signal to your neighbor? Remember, your neighbor may actually be you.
1. Which aspect of the experiment does Paragraph 2 mainly concern?| A．Its finding. | B．Its application. | C．Its purpose. | D．Its design. |
| A．By connecting their roots. | B．By opening their leaf pores. |
| C．By spreading a special smell. | D．By leaking certain chemicals. |
| A．Confidential. | B．Cooperative. | C．Long-distance. | D．Air-to-air. |
| A．To better its surroundings. | B．To make itself strong. |
| C．To develop its root. | D．To keep itself safe. |
【推荐3】Earth is lighted up by bioluminescence but, for many of us, seeing the natural phenomenon is a rare treat: Catching the glow of a firefly or witnessing a dolphin swimming through electric blue waters is a thrill.
Researchers are currently engineering glowing flowers and decorative plants that can cast a green light onto our living rooms. Observing a plant’s health via its glow can be a way to instantly measure its health, and the side-effect is anybody who wants a healthy glowing plant in their living room can have one.
A study published on Monday in Nature Biotechnology shows that this goal is well on its way to being a reality. The study authors announce they’ve created a method that causes plants to glow much brighter, and for a longer period of time, than previous efforts. Plants adapted by this method should be available for purchase within a few years.
The research was conducted through a teamwork between three scientific institutions and Planta, a biotech startup in Moscow. When this team examined a poisonous mushroom, they discovered that caffeic acid is responsible for its bioluminescence. In this new study, the team employed that information and inserted enzymes — which are specific to the mushroom — into the DNA of tobacco plants. In turn, the enzymes were able to interact with the caffeic acid in the tobacco plants, and cause them to glow both in the dark and in the daylight.
This method, the scientists claimed, made the plants 10 times brighter than previous efforts and the continuous light production didn’t harm the health of the plants. Interestingly, the light decreased as the leaves aged — but it also increased when the leaves were damaged. In turn, the team suggested this method could also help other researchers monitor plant responses to various pressures and changes in the environment. If a plant is short of water or a hungry sheep is harming a plant, bioluminescence could warn of this damage before it’s too late.
1. How can people quickly identify a decorative flower’s health condition?| A．By making it greener. | B．By monitoring its glow. |
| C．By testing the chemicals in it. | D．By putting it in the living room. |
| A．They will appear on the market. | B．They may take the place of lamps. |
| C．They can light up a whole living room. | D．They glow less bright than previous efforts. |
| A．They inserted caffeic acid into it. |
| B．They made it give out brighter light. |
| C．They grew it on the tobacco plant farm. |
| D．They put its enzymes into the tobacco plants. |
| A．Warning of potential damage from glowing plants. |
| B．Warning of the light production’s harm to plants. |
| C．Effects of continuous light production on the glowing plants. |
| D．Benefits of combining specific enzymes with caffeic acid in plants. |
