1 . Plants don’t have ears or a central nervous system, but new research out of the University of Missouri has demonstrated that they might still have the ability to “hear”. More specifically, plants have been shown to exhibit an immune (免疫) response to the mere sound of a hungry insect.
For the study, researchers played the sound of a caterpillar chewing to a group of plants, which caused slight vibrations (振动) on the plants’ leaves. The plants were able to recognize these vibration patterns as danger, and responded by mounting the appropriate immune response. In other words, it appears that plants can “hear” themselves being chewed on.
Researchers assume that plants achieve this remarkable ability thanks to proteins that respond to pressure found within their cell membranes. Vibrations cause pressure changes within the cell, which can change the behavior of the proteins; however, additional study will be required to confirm or deny this theory.
Once researchers identify the exact mechanisms at play in this process, it could lead to advances in crop protection. Farmers could potentially learn to use sound to cause a plant’s natural chemical defenses against insect threats, rather than turning to poisonous chemicals.
“We can imagine applications of this where plants could be treated with sound or genetically engineered to respond to certain sounds that would be useful for agriculture,” said study author Heidi Appel.
The study adds to the growing list of ways that plants have been shown to sense their environments. They are not the boring organisms that many people assume they are. For instance, some plants are able to communicate with each other and signal upcoming danger to their neighbors by releasing chemicals into the air. Plants can respond to light (think about sunflowers) and temperature. Some can even respond to touch, such as the Venus flytrap (捕蝇草), which snaps shut when an insect stimulates its hairs.
1. Why did researchers carry out the study?A.To find out if plants can react to sounds. |
B.To learn how plants recognize dangers. |
C.To discover if plants can shake their leaves. |
D.To see how plants improve immune systems. |
A.To remove insects. | B.To protect crops. |
C.To treat plant diseases. | D.To produce chemicals. |
A.There are more plants than we know. |
B.Plants are more active than we think. |
C.Plants fit in well with their environments. |
D.Lots of secrets about plants remain unclear. |
A.Can plants “talk” with each other? |
B.How do plants make use of sounds? |
C.Can plants “hear” themselves being eaten? |
D.How do plants defend themselves against attacks? |
2 . Looking for a big-leafed houseplant that will make a statement in your room and decorate yourhome? If so, then you’ve come to the right place!
Peace Lily
Extremely easy to look after, this popular, flowering plant is very tolerant and undemanding. It is a beloved houseplant for its large, glossy oval leaves and unusual white spoon-shaped flowers. Typically blooming in the spring, this lovely plant can effectively brighten up a living space.
African Mask Plant
This indoor plant is a smaller plant with large dark green leaves that are shaped like a heart. Native to tropical (热带的) parts of Africa, it prefers high heat and high humidity. That can be somewhat a tricky task for the average plant owner to achieve in their home, who is likely to have trouble duplicating (复制) these steamy conditions.
Snake plant
Commonly referred to as mother-in-law’s tongue, it is one of the easiest houseplants to take care of. With tall, twisting sword-shaped leaves that grow upright, it has air-purifying capabilities and can merrily grow in almost dark corners of the house. But the plant is poisonous to dogs and cats, so it’s wise to keep this plant away from them, if your pets are plant chewers.
Kentia Palm
Caring for the Kentia Palm plant is very straightforward, which can be neglected for weeks at a time. Quite enjoying a bit of shade, it has big leaves that grow from a narrow base and is great for filling a corner without taking up much floor-space. Place it in front of a blank wall, and its archingfronds (大型复叶) will cast beautiful shadows.
1. Which of the following requires an experienced plant owner?A.Peace Lily. |
B.African Mask Plant. |
C.Snake plant. |
D.Kentia Palm. |
A.It poses little danger to dogs and cats. |
B.It is better for purifying air than others. |
C.It gets its name from a poisonous snake. |
D.It grows well in shady areas of the house. |
A.Distinctive leaves. |
B.Flowering season. |
C.Growth temperature. |
D.Striking size. |
1. What kind of area do Bill and Sally live in?
A.A hot area. | B.A high area. | C.A dry area. |
A.They are gardeners. | B.They are designers. | C.They are builders. |
A.Trees. | B.Glass houses. | C.Fences. |
A.Successful. | B.Unsatisfactory. | C.Impossible. |
4 . The rapid pace of global warming and its effects on habitats raise the question of whether species are able to keep up so that they remain in suitable living conditions. Some animals can move fast to adjust to a swiftly changing climate. Plants, being less mobile, rely on means such as seed dispersal(传播) by animals, wind or water to move to new areas, but this redistribution typically occurs within one kilometre of the original plant.
When the climate in a plant’s usual range becomes hotter than it can tolerate, it must find new, cooler areas that might lie many kilometres away. One explanation for long-distance seed dispersal is through transport by migratory (迁徙的) birds. Such birds swallow seeds when eating fruit and can move them tens or hundreds of kilometres outside the range of a plant species.
Gonzáiez-Vary and colleagues report how plants might be able to keep pace with rapid climate change with the help of migratory birds. The authors analysed the fruiting times of plants, patterns of bird migration and the interactions between fruit-eating birds and fleshy-fruited plants across Europe. Plants with fleshy fruits were chosen for this study because most of their seed transport is by migratory birds, and because fleshy-fruited plants are an important part of the woody-plant community in Europe. The common approach until now has been to predict plant dispersal using models fitted to abiotic (非生物的) factors such as the current climate. Gonzáiez-Vary instead analysed an impressive data set of 949 different seed-dispersal interactions between bird and plant communities, together with data on entire fruiting times and migratory patterns of birds across Europe. The researchers also analysed DNA traces from bird wastes to identify the plants and birds responsible for seed dispersal.
1. How do species adapt to climate changes when it’s too hot?A.All animals will move away across great distanced. |
B.Some plants depend on migratory birds to carry seeds. |
C.Some plants depend on animals, wind or water to move. |
D.Plants’ seeds disperse to cooler places of several kilometres away. |
A.Most of these can’t fit rapid climate change |
B.Migratory birds like making nests in them |
C.Migratory birds transport their seeds. |
D.They are favoured by most birds. |
A.To explain relations between fruit plants and migratory birds. |
B.To clarify the reason why birds migrate in fruiting times. |
C.To present a fact that migratory bird eats flesh fruits. |
D.To show that fruits depend on migratory birds. |
A.The advantage of fruit plants. |
B.The destination of the bird migration. |
C.The adaptation of fruit plants to the climate change. |
D.The influence of climate change on plants and animals. |
It’s been nearly seven years since a group of volunteers grew flowers at What Cheer Flower Farm in Rhode Island, with a simple goal: get flowers into the hands of anyone in need. Best of all, each one of the tens of thousands of flowers that What Cheer grows and
What Cheer was founded by two gardeners
What Cheer’s flower beds lie in an industrial neighborhood that once
“Not only do we give this space back to the neighborhood,” says Achen, “but we are also an eco-friendly spot with the ability to help local insect and bird
6 . Flower scents (香味) help pollinators (传粉者) locate their favorite plants. Scientists have established that air pollutants change those scents, throwing off the tracking abilities of such beneficial insects as honeybees. But new lab experiments are the first to confirm that one pollinator, the tobacco hawkmoth, can quickly learn that a pollution-changed scent comes from the jasmine tobacco flower that the insect likes.
Chemical ecologist Markus Knaden and colleagues focused on one pollutant-ozone, the main element in smog. In the lab, his team blew an ozone-changed scent from a tiny tube into a tunnel, with a moth (飞蛾) awaiting at the far end of the tunnel. Usually, when the moth smells the unchanged scent, it flies upwind and uses its long, skinny mouthparts to probe the tube the way that it would a flower. The researchers expected that the changed scent might throw the moth off a little. But the insect wasn’t attracted at all.
In addition to scent, tobacco hawkmoths track flowers visually, so Knaden’s team used the feature, along with a sweet snack, to train the moth to be attracted to a pollution-changed scent. The researchers wrapped a brightly-colored artificial flower around the tube to trick the moth back across the tunnel, despite the unfamiliar scent. And the team added sugar water to the artificial flower. After a moth was given four minutes to taste the sweet stuff, it was attracted to the new smell when sent into the tunnel 15 minutes later, even when neither the sugar water nor the visual signal of the artificial flower was present.
This study focused on only one moth species, but Knaden’s team is now working on planning experiments with other pollinators that are easier to follow than tobacco hawknoths. While he guesses honeybees might also be as adaptable as the moth was, that won’t be true of every pollinator. “The situation can become very bad for insects that are not as clever or cannot see that well. I don’t want the take-home message to be that pollution is not a problem.”
1. What does the underlined word “probe” in paragraph 2 mean?A.Surround. | B.Favour. | C.Access. | D.Examine. |
A.not all moths were attracted to ozone-changed scent as expected |
B.the current research conducted by Knaden is pioneering and wide-ranging |
C.not all pollinators are adaptable to human-driven changes to their environment |
D.the moth didn’t like the new smell without sugar water and artificial flower |
A.Positive. | B.Cautious. | C.Unclear. | D.Critical. |
A.A moth can be rid of the tracking ability to locate its favourite plants. |
B.A moth is able to establish a relationship between pollution and scents. |
C.A moth may outsmart smog by learning to like pollution-changed scent. |
D.A moth is born with an ability to adapt to the changes in the environment. |
7 . A lot of health care are connected with being around trees.
They also do a great deal of good for the environment by reducing air pollution and taking in carbon dioxide from the atmosphere.
A tree’s ability to take in carbon dioxide is especially useful when the tree.is in cities or towns, where there are too many industrial activities. For the study, the researchers used laser scanning methods to take their own carbon readings of trees from the ground as well as the air.
They determined that Camden had a median carton density (浓度) of around 55 tons of carbon per hectare (t/ha). Greener areas of the borough, like Highgate Cemetery, had a carbon density of 380 t/ha — levels that are typically seen in rainforests.
So what exactly does this mean? Trees could help cool the atmosphere by removing carbon dioxide from the air. However, some climate scientists argue that it’s more complicated (复杂的) than that.
A.We need to protect the ones we already have. |
B.Global warming is happening at a faster rate than ever. |
C.These benefits aren’t just felt in the countryside, either. |
D.For comparison, major cities in the US have a carbon density of 7.7. |
E.They have been known to reduce people’s stress and improve overall mental health. |
F.Then they compared their findings with the data from the UK Environment Agency. |
G.They think the impact of tree-planting activities today may not be seen for many years. |
8 . Sunflowers have increasingly become popular on social media. People enjoy the bright yellow flowers and take pictures of themselves in bright fields of sunflowers, which are called “sunflower selfies.”
Actually, it is easy to grow your own sunflowers. Here are some instructions.
Do you want to start growing sunflowers from seeds?
Then, plant each seed into soil apart. Keep the soil wet, but not too wet, until the seeds begin to grow. During the growth process, you should water regularly the plants. When they grow up, it is best to put up some shelves to protect the plants from strong winds.
When seeds will start coming out of the head, it is time for harvest. Cut the flowers off and put them into a bag or container. In this way, the seeds will not fall out. Then remove the seeds by rubbing flowers with your hands or a hard brush over a container.
Finally, you’d better select those full seeds for food.
A.Equally attractive is the delicious taste. |
B.Sunflower seeds may be eaten cooked or uncooked. |
C.You can also tie the plants to something tall for support. |
D.Some kinds of sunflowers can grow up to three meters tall. |
E.It is important to loosen the soil before the seeds are planted. |
F.Put the selected seeds in room-temperature water for 2-8 hours. |
G.They will develop long roots that work their way deep into the ground. |
9 . We are learning more and more every day about just how smart some animals are: monkeys, some species of birds, dogs, cats. But how about other animals? Snails? Mosquitos? They sure seem less smart. Still smarter than plants, though. Because it would be difficult to argue that plants are intelligent. Or would it?
In a new study, it was shown that plants send out sounds when they are sad. And these sounds are very different depending on whether they have recently been cut or whether they don’t have enough water. The sounds can’t be heard by human ears, as they are between 20 and 100 kilohertz, which is above the bottom of human hearing (which usually has the upper limit of 15-17 kilohertz).
These are fantastic results: plants don’t suffer in silence; they are screaming with pain. That is exactly what the popular science press has been doing.
There is no evidence that they are heard by anyone although theoretically (理论上) some animals — bats, moths, mice — could actually hear it as their ears are sensitive to the plant sounds. And it could very well be a byproduct (副产品) of the physical condition of these plants: less water in the system leads to more air bubbles (气泡) in plants, which leads to the sound of the popping of these bubbles.
Is this a disappointing explanation? I don’t think so. The aim is to understand why plants do what they do. And the results about the sounds contribute to this body of knowledge. They could even lead to better ways of controlling the needs of plants in gardening by sound observation.
All of this is true even if the plants don’t strictly “cry” or “scream”.
1. Why are we unable to hear the sounds of plants?A.Because they are imagined by humans. |
B.Because they go beyond human hearing. |
C.Because plants don’t actually give off sounds. |
D.Because plants are not as intelligent as animals. |
A.Plants keep silent even when they suffer. |
B.Water in the plants sends off different sounds. |
C.The plant sounds might show their feelings or needs. |
D.The study aims to control the needs and feelings of plants. |
A.Because plants don’t actually “cry” or “scream”. |
B.Because the results prove their knowledge of plants. |
C.Because the results show that-plants understand what they do. |
D.Because plants’ demands could be met by observing their sounds. |
A.Plants suffer in silence | B.Plants “cry” in pain |
C.Plants “scream” with joy | D.Plants need attention |
10 . From Latin America to Sichuan province, chili peppers and their famous burning taste have become a worldwide sensation (热门) .But how could something that burns so hot possibly be any good for people?
In a study by researchers at Marshall University in the Us, scientists made the first complete description of capsaicin (辣椒素)—a chemical found in spicy chilies—and its anti-cancer properties. Although capsaicin is not normally a good medicine due to some negative properties such as its spicy flavor, the study found that there are ways to bring out its anti-cancer benefits while overcoming these negatives.
In nature, capsaicin evolved as a defense mechanism in plants to drive away unwanted animals while attracting those that could spread the seeds, such as birds which cannot taste or feel the spice. From a scientific point of view, capsaicin works by triggering a pain receptor called TRPV1, causing the body to react as if it had actually touched something hot and dangerous. Yet, this natural repellent (驱虫剂) for most animals has instead become a favorite food for many people, often called “chiliheads”.
So, what is it that attracts humans to capsaicin, chili peppers and spicy food in general? Besides its many health benefits — such as pain relief, weight loss, and body heat regulation—people love eating chili peppers precisely because it hits the pain receptors in just the right way.
As Scientific American noted: “People seem to enjoy — and actively seek out—many other sensations ... the sensation of falling provided by roller coasters or skydiving, the feelings of fear and anxiety while watching horror movies, the physical pain experienced upon jumping into icy water, or even the feelings of sadness that come while watching a tearjerker.”
So, the next time you bite into a hot chili pepper, remember: its not just healthy, but fun too!
1. What can we learn from the result of the study by researchers at Marshall University?A.The study describes capsaicin for the first time. |
B.Capsaicin contributes to the prevention of cancer. |
C.There is a chemical called capsaicin in spicy chilis. |
D.The negative features of capsaicin cannot be overcome. |
A.It stops birds from eating plants. |
B.It causes more seeds to be produced. |
C.It attracts some animals to distribute seeds. |
D.It helps plants survive in hot or dangerous situations. |
A.By illustration. | B.By statistics. |
C.By comparison. | D.By definition. |
A.Why some people enjoy spicy food. | B.How chili peppers are so burning. |
C.How plants benefit from capsaicin. | D.Where capsaicin can be found. |