1 . Between 20 and 40 per cent of planet Earth is covered in grasslands, across every continent except for Antarctica. Grass is a low-growing, flowering plant with groups of narrow leaves growing from its base. Strong roots typically hold this plant’s leaves firmly to the ground.
One of the most common sights along stretches of grass is grass-eating animals. This is because many large animals rely on extensive grasslands to survive, and grass grows well with this regular trimming (修剪). The plants gain their energy from sunlight and require healthy cells to do so. If the leaves aren’t cut, the tips die and start to rot. When they are damaged with a clean cut, however, the cells are caused to grow quicker and produce new, healthy tissue. This is also why cutting your garden’s grassland regularly can make your grass look thicker and healthier.
Humans rely on grass for food, too. Many grasses, such as w heat or corn, are harvested as a main part of some diets. Meanwhile, grass is used indirectly to produce food in the form of livestock (牲畜). Cattle farmers require grass in their fields to feed cows and sheep before they are turned into meat for human consumption.
One of the most debated questions is how long ago grass evolved. Because grass doesn’t preserve well as a fossil, a definitive answer is hard to come by. Until recently, many scientists estimated that grass began to grow on Earth between 50 and 65 million years ago.
However, within the last decade, a piece of 100-million-year-old amber (琥珀) was found that appeared to contain the oldest grass fossil to date. Studies of fossilized dinosaur faces (粪便) also suggest that some dinosaurs lived at the same time that grass grew on the planet, incorporating it into their diets.
1. What is the function of the roots mentioned in Paragraph 1?| A．To fix the leaves to the soil. | B．To store water and nutrients. |
| C．To support the growth of the plant. | D．To protect the plant from animals. |
| A．By improving soil quality. | B．By encouraging cell growth. |
| C．By preventing the tips from dying. | D．By attracting more animals to eat them. |
| A．Grass doesn’t preserve well as a fossil. | B．There are no fossils of grass available. |
| C．There is no solid evidence of its evolution. | D．Scientists can’t agree on its origin. |
| A．The Variety of Grass | B．The Development of Grass |
| C．How Grass Change Life | D．How to Make Grass Grow Well |
2 . Four Best Plants to Give as Gifts
Choosing a gift for someone is always a challenge. Giving plants is one way to try if the recipient is already a plant-lover. Here are some sure to impress as thoughtful gifts.
Jade Plant
The jade plant is a large succulent (肉质植物) that makes a perfect gift for someone who’s mastered parenting succulents. With a woody stem (茎), it looks like a tree once growing tall enough. Besides occasional watering and a bright window, the jade plant has few other requirements. A good challenge for ambitious owners is to regularly cut off its heavy leaves to reduce weight.
Christmas Cactus
This is a succulent with eye-catching flowers that appear in winter. You might assume it a picky plant, but nothing could be further than the truth. It prefers bright, indirect light and grows well in average potting soil. This plant prefers a steady watering schedule, especially in winter. To encourage more growth, plant it in a hanging container that allows its branches to hang down.
Paperwhite
Some people just aren’t interested in keeping houseplants around long-term, and paperwhite flowers are an excellent gift for anyone you know who fits this mould. Paperwhites grow from bulbs (鳞茎) and will produce flowers out of season. The roots need to be kept relatively damp, but once they are blooming (开花), there’s not much that can go wrong. They can be replanted outside after they have run their course.
Corn Plant
The corn plant is forgiving of variable light conditions and watering routines. It grows slowly, but can reach a height of four to six feet, and can make an impressive floor plant. Its leaves turn paler in direct sunlight to reflect the extra light, and darker green in shady conditions to maximize sunlight absorption.
1. Which plant requires practised gardening experience?| A．Jade plant. | B．Christmas cactus. | C．Paperwhite. | D．Corn plant. |
| A．By replanting it outside before blooming. | B．By watering it regularly during blooming. |
| C．By cutting off most of its heavy leaves. | D．By making its branches grow upwards. |
| A．The frequency of watering. | B．Its flowering time. |
| C．Its rate of growing. | D．The amount of sunlight. |
3 . Scientists have been experimenting with playing sounds to plants since at least the 1960s, during which time they have been exposed to everything from Beethoven to Michael Jackson. Over the years, evidence that this sort of thing can have an effect has been growing. One paper, published in 2018, claimed that an Asian shrub known as the telegraph plant grew substantially larger leaves when exposed to 56 days of Buddhist music — but not if it was exposed to Western pop music or silence. Another, published last year, found that marigolds and sage plants exposed to the noise of traffic from a busy motorway suffered growth difficulty.
Plants have been evolving (进化) alongside the insects that eat them for hundreds of millions of years. With that in mind, Heidi Appel, a botanist now at the University of Houston, and Reginald Cocroft, a biologist at the University of Missouri, wondered if plants might be sensitive to the sounds made by the animals with which they most often interact. They recorded the vibrations made by certain species of caterpillars (毛毛虫) as they chewed on leaves. These vibrations are not powerful enough to produce sound waves in the air. But they are able to travel across leaves and branches, and even to neighbouring plants if their leaves touch.
They then exposed tobacco plant — the plant biologist’s version of the laboratory mouse — to the recorded vibrations while no caterpillars were actually present. Later, they put real caterpillars on the plants to see if exposure had led them to prepare for an insect attack. The results were striking. Leaves that had been exposed had significantly higher levels of defensive chemicals, making them much harder for the caterpillars to eat. Leaves that had not been exposed to vibrations showed no such response. Other sorts of vibration — caused by the wind, for instance, or other insects that do not eat leaves — had no effect.
“Now speakers with the right audio files are more often being used to warn crops to act when insects are detected but not yet widespread,” says Dr. Cocroft. “Unlike chemical pesticides, sound waves leave no dangerous chemicals.”
1. What can we learn about plants from the first paragraph?| A．They may enjoy Western music. | B．They can’t stand Buddhist music. |
| C．They can react to different sounds. | D．They can make different sounds. |
| A．Plants can make a cry for help. | B．Plants evolve alongside insects. |
| C．Plants are sensitive to the sounds. | D．Plants have been studied for years. |
| A．They can recongnize harmful vibrations. | B．They look like laboratory mice. |
| C．They can threaten the caterpillars. | D．They can release poisonous chemicals. |
| A．Disadvantages of chemical pesticides. | B．Application of the experimental results. |
| C．Interaction between plants and insects. | D．Warning system of widespread insects. |
4 . Some of the oldest living things on our remarkable planet are trees. The record holders are bristlecone pines (狐尾松) of the western United States, quite a few of which are known to be more than 3,000 years old. One individual, discovered in 2012, is estimated to be more than 5,060 years old, making it the oldest known non-clonal tree in the world!
So, how do trees survive for thousands of years?
The other part of the answer has to do with how trees age. In fact, there is quite a debate about whether ancient trees can be considered “immortal (永生的)”. That is, will such trees ever die if they are not killed by an outside force? We may never know the answer to that, but, at the very least,
Older trees benefit greatly from having bodies made mostly of dead woody tissue. In fact, an old tree might be as much as 95 percent dead tissue! Given that it isn’t alive, wood does not require metabolic (新陈代谢的) activity to maintain it,
| A．so an old tree doesn’t really need to do much to keep living |
| B．This is a question that has something to do with the good luck of trees |
| C．However, bristlecones are certainly not alone in terms of the oldest creatures |
| D．This is a fascinating question for biologists that does not yet have a settled answer |
| E．What’s more, some ancient trees have superior chemical defenses against pests and diseases |
| F．which means that trees can survive everywhere without being limited by external and internal conditions |
| G．we know that ancient trees age in ways that are dramatically different from the ways that most animals and even other plants age |
5 . Britain has a stubborn enemy called the “devil plant”, the Japanese knotweed (虎杖). The name originated in Japan, but it became a promoter behind a plant disaster in Britain. Initially it was introduced to England as a landscape plant. However, over time it has evolved into a harsh plant difficult to control.
The plant is disreputable (坏名声的) mainly because of its strong ability to survive. The Japanese knotweed can grow at an amazing speed. What’s more, Japan’s knotweed is penetrating. As long as you give it a small gap, it can follow it and make rapid growth. This gap may be a crack in the road, or a wall crack in the house, and even some Japanese knotweed will start to grow from the foundation of the house, gradually “destroy” the whole house. Such an invasion (入侵) is a nightmare for the British. The British simply love and hate the plant, but so far, they are still unable to find an effective way to remove it.
Fortunately, China’s knotweed is not identical to Japan’s, and in the China’s ecosystem, there are many natural enemies against it. As a result, China has not experienced a knotweed invasion as severe as Britain. Additionally, its tender stem can be made into delicious food. The root of knotweed is a very good Chinese medicine. Therefore, in some places there’s also a need to plant knotweed, to obtain economic benefits.
This case gives us a profound inspiration that it is important to be careful when introducing alien species and to fully understand the characteristics of plants or animals and the effects they may cause in a new environment, otherwise it may be easy to spend a huge amount of money every year to clean up the Japanese knotweed, as in the UK.
1. Why did Britain bring in Japanese knotweed at first?| A．To make profits. | B．For decoration. |
| C．For scientific research. | D．To promote biodiversity. |
| A．Fading away. | B．Dying out. |
| C．Multiplying rapidly. | D．Growing steadily. |
| A．China’s ecosystem is not damaged by knotweed. |
| B．Knotweed is in great demand in the whole China. |
| C．Knotweed has made most of the Chinese people rich. |
| D．Chinese medicine includes knotweed’s stems and roots. |
| A．A Natural Phenomenon We Know |
| B．A Plant That People Love and Hate |
| C．Alien Species’ Effect on the Local Economy |
| D．The Fight Against Invasive Plants and Animals |
6 . Scientists have shown how plants can protect themselves against genetic (基因的) damage caused by environmental stresses. The growing tips of plant roots and shoots have an in-built mechanism (机制) that spells cell death if DNA damage is detected, avoiding passing on faulty DNA.
Plants have small populations of stem cells (干细胞) at the tips of their roots and shoots, which enable them to continuously grow and produce new tissues throughout their lifetime. These stem cells serve as ancestors for plant tissues and organs. However, any genetic faults present in the stem cells will continue to exist and be passed on permanently throughout the plant’s life, which could last thousands of years.
Given the critical role of stem cells and their exposure to potentially dangerous environments at the growing tips of roots and shoots, safeguards are necessary to prevent stem cell faults from becoming fixed. Researchers Nick Fulcher and Robert Sablowski, funded by the Biotechnology and Biological Sciences Research Council, aimed to uncover these protective mechanisms. Through experiments involving X-rays and chemicals, they discovered that stem cells were more sensitive to DNA damage compared to other cells.
When DNA damage occurs, the cells have the capacity to detect it and cause programmed cells to die, preventing the propagation of the damaged genetic code to the rest of the plant tissues. This process has similarities to the safeguard mechanism found in animal cells, which has been broadly studied due to its relevance in preventing cancer.
The identification of a similar protective system in plants is of great interest in the field of plant development. It also helps scientists develop plants that can better handle environmental stress. So knowledge of how plants deal with these stresses is of fundamental significance to agricultural science’s response to climate change.
1. What is the function of the in-built mechanism in plants?| A．To produce more roots and shoots. | B．To increase the overall lifetime of the plant. |
| C．To enhance plant growth and nutrient intake. | D．To stop genetic faults in stem cells passing on. |
| A．They are relatively abundant in quantity. | B．They are resistant to environmental stresses. |
| C．They make quick response to DNA damage. | D．They have the ability to repair damaged DNA. |
| A．Spread. | B．Change. | C．Existence. | D．Self-repair. |
| A．The way of dealing with climate change on the earth. |
| B．The significance of identifying the protective system in plants. |
| C．The method of ensuring plant survival under environmental stress. |
| D．The urgency of developing plants that can handle environmental stress. |
7 . Imagine if your houseplant was thirsty and it could tell you so. Chances are, it can—you just can’t hear it. According to the findings from researchers in Israel, tomato and tobacco plants stressed from lack of water or having their stems (茎) cut make sounds comparable in volume to normal human conversation.
The sound is kind of a snap (咔嚓声) and pop. While the frequency of the plant outcry is too high for our ears, they can likely be heard by insects, other animals and other plants.
The team started with healthy and stressed tomato and tobacco plants—the stressed ones were either unwatered for several days or had their stems cut. They recorded the group in an acoustic chamber (隔音箱) and then in a noisier greenhouse. They also used a machine-learning algorithm (算法) to distinguish between happy plants, thirsty plants, and cut plants.
The team found that stressed plants make more sounds than unstressed plants, with a stressed plant making 30 to 50 clicks per hour at seemingly random intervals. Unstressed plants were much less active.
“Water-stressed plants began making noises, and the frequency of sounds peaked after five days with no water before decreasing again as the plants dried up completely. The types of sound differed with the cause of stress,” according to a press release for the research. “The machine-learning algorithm could accurately distinguish between lack of water and stress from cutting and could also tell whether the sounds came from tomato or tobacco plants.”
The researchers explain that it’s unclear whether the sounds result from an effort to communicate—yet they note that the sounds have ecological and evolutionary meaning. “It’s possible that other organisms could have evolved to hear and respond to these sounds,” says Hadany. “For example, an insect that intends to lay eggs on a plant or an animal that intends to eat a plant could use the sounds to help guide their decision.”
1. What did the Israel researchers find?| A．Plants cry loudly when they are cut | B．Certain plants like to help each other. |
| C．Plants communicate as humans do. | D．Certain stressed plants make sounds. |
| A．Why a noisier greenhouse was used. | B．How the researchers did the research. |
| C．The importance of recording the plants. | D．The varieties of plants for the study. |
| A．The moment they were lack of water. | B．When the experiment began. |
| C．After five days of water shortage. | D．After drying up completely. |
| A．They are of much significance, | B．They help animals escape danger. |
| C．They affect the ecological balance. | D．They are mainly for communication. |
8 . Warmer oceans can cause coral (珊瑚) bleaching. Bleaching happens when the coral, colonies of tiny animals called polyps, lose colored algae (藻类) living in their bodies and turn completely white. Without the algae, the coral loses its main food source and can die.
In 2021, the United Nations reported a 14 percent loss of corals across the world largely from rising sea temperatures in the previous 13 years. Australia declared mass bleaching events in 2022 across large parts of the Great Barrier Reef, the fourth since 2016.
Reefs in Hawaii, Florida, and the Caribbean were all severely affected, but thankfully some coral areas were not. Scientists looked into the characteristics of these corals and their ecosystems to see how others could be protected. Warm water reefs in the tropics are the worst affected by bleaching, but they also contain corals with better heat resistance.
Research is focused on finding genes for heat tolerance so that they can be passed on to future generations. Biologists mix corals that are more resilient to higher temperatures with those that are not and the resulting hybrid generation has a better chance of survival.
Researchers in Florida’s reefs have been using ocean nurseries to replant coral with batches that contain genes resistant to heat, acidification, and disease. Those areas have recovered within a year.
Other projects like Revive and Restore are using methods like preserving older coral populations’ sperm and eggs (biobanking) and using corals with better adaptability characteristics in breeding. The project also believes that boosting biodiversity by restoring (恢复) seabirds to islands, and ridding them of invasive species like rats, helps coral reefs thrive.
Ultimately, scientists say that without a serious reduction in greenhouse gas emissions, 99 percent of the world’s coral reefs will be gone by the end of the century. There is a limit to how quickly coral can adapt, especially given the rate of climate change. Computer simulations have shown that mild or moderate warming allows coral to adapt, but if temperatures rise rapidly then extinction is certain.
1. What mainly causes coral bleaching?| A．Loss of algae. | B．Lack of food. |
| C．Warm oceans. | D．Ocean pollution. |
| A．Coral reefs in tropics are easier to bleach. |
| B．Some corals are found better to resist heat. |
| C．Coral reefs in some areas are badly affected. |
| D．Ecosystems in some coral areas are destroyed. |
| A．Breeding hybrid generation with heat resistance. |
| B．Replanting batches of corals containing diseases. |
| C．Restoring seabirds of islands and invasive animals. |
| D．Setting no limitation of greenhouse gas emissions. |
| A．Botany. | B．Culture. | C．Nature. | D．Education. |
9 . 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. |
10 . Tree-planting, intended to help draw down carbon dioxide from the atmosphere, has become a synonym (同义词) for climate action. In our constant focus on trees, we’ve developed a fixed understanding: Trees absorb carbon dioxide, end of story. The reality is that trees don’t grow well alone. They exist within complex communities, helped along by each other as well as the animals they coexist with. The woodland isn’t nature’s only carbon sink: Grasslands and oceans also help reduce the carbon level and rely on a healthy amount of biodiversity.
That’s what the paper, published in Nature, wants to get across. Co-author Oswald J. Schmitz, a professor of ecology at Yale University, said trees might not be able to do their carbon-uptake job efficiently without the right animals in their ecosystem. That’s because animals animate the carbon cycle through their behavior and roles in the ecosystem. He added that the very presence of wild animals could cause feedback effects that change the ecosystem’s capacity to absorb, release, or transport carbon.
In Serengeti, for instance, the sharp decline in wildebeest (角马) population s during the mid-20th century allowed grass to grow wildly, eventually promoting wildfires that consumed 80 percent of the ecosystem annually and led to a net release of carbon dioxide into the atmosphere. When disease management and bans on illegal hunting helped animal populations recover, a greater share of the carbon stored in plants was consumed by wildebeest and released as waste, keeping it in the system and restoring the grassland as a carbon sink.
Researchers rarely consider wildlife conservation as a strategy to increase an ecosystem’s carbon storage capacity, said Schmitz. “They think that animals either aren’t important enough or that you can’t take up carbon and conserve animals at the same time,” he said. “Our message is that you can and should. It can be a win-win for both biodiversity conservation and carbon uptake.” We need a full picture-with both trees and animals-to explore nature’s full potential.
1. What can we learn from the first paragraph?| A．Actions are needed to reduce carbon dioxide. | B．Trees are a quick solution to the climate crisis. |
| C．People are not thinking through trees properly. | D．Grasslands and oceans help maintain biodiversity. |
| A．Activate. | B．Restart. | C．Disturb. | D．Break. |
| A．The conservation of animals is still a serious issue. |
| B．Animals can swing the ecosystem’s capacity to store carbon. |
| C．Human impacts bring about the reduction in wildlife populations. |
| D．The increase in animal species causes a decrease in carbon uptake. |
| A．Animals Adjust Themselves to Climate Change |
| B．Woodland Isn’t the Only Carbon Sink on the Earth |
| C．The Serengeti Ecosystem Needs Urgent Improvement |
| D．Trees May Fail to Fulfil Their Duties without Animals |
