1 . Do you know forests are one of our planet’s greatest carbon sinks? This means that they absorb an enormous amount of carbon released into the atmosphere, a greenhouse gas that contributes to climate change and the earth’s rising temperature.
The poplar tree, standing tall and regal, is known for its fast-growing nature and its gray, white, or black bark. A biotechnology firm in San Francisco, CA, genetically modified poplar trees. According to a four-month study conducted in their greenhouse, the engineered trees grew 53% larger than their normal counterparts and stored 27% more CO2. In February 2023, the company also planted modified poplar trees in southern Georgia. This marks the first time in the United States that engineered trees have been planted outside of a controlled lab setting!
All plants experience photosynthesis (光合作用), where sunlight, water, and CO2 are transformed into glucose and oxygen. However, almost all trees release a poisonous substance in the process. To remove this substance, trees must use up newly-produced energy in another step known as photo-respiration (光呼吸作用), which does not produce any energy and releases CO2 back into the atmosphere. To prevent plants from wasting their energy, the biotechnology firm engineered their poplar trees with genes found in green algae. First tested in tobacco plants, the foreign genes change the poisonous substance produced by trees into sugars, so that more energy can be used for removing carbon and tree growth.
Researchers from the company are planting their poplar trees on private land that has been previously disturbed, such as abandoned coal mines in Pennsylvania. The modified trees will be planted between natives like sweet gum and bald cypress to boost biodiversity and maintain soil fertility (肥沃).
Plant biologist Norberto Martinez from the University of Illinois suggests the engineered poplar trees may not thrive outdoors or will require more water and fertilizer to maintain their fast growth. Many sustainable forestry organizations have also banned engineered trees from being planted in forests. The Global Justice Ecology Project argued that these trees could interfere with efforts to protect and regenerate forests.
Though there may be opposing opinions regarding genetically modified poplar trees, one thing is for sure: they hold the potential to lower greenhouse gases in our environment at a faster rate. This company’s attempt is certainly an innovative approach to the ongoing climate crisis.
1. What is Paragraph 3 mainly about?| A．The necessity to absorb CO2. | B．The basic idea behind engineered trees. |
| C．The effect of photosynthesis on plants. | D．The importance of energy transformation. |
| A．Save. | B．Measure. | C．Interrupt. | D．Strengthen. |
| A．Their first planting state was Pennsylvania. |
| B．Their potential to absorb CO2 outweighs concerns. |
| C．They can release more oxygen than normal poplar trees. |
| D．They will grow better if planted away from normal plants. |
| A．inform and argue | B．analyse and advise |
| C．argue and discuss | D．examine and assess |
2 . In a tiny, lab-grown garden, the first seeds ever sown in lunar dirt have come up. This small crop, planted in samples (样本) returned by Apollo tasks, offers hope that astronauts could someday grow their own food on the moon.
But plants planted in lunar dirt grew more slowly and were thinner than others grown in volcanic(火山的) material from Earth, researchers report 12 May in Communications Biology. That finding suggests that farming on the moon would take a lot more than a gardening skills.
“Ah! It’s so cool!” says a botanist (植物学家) Richard Barker. “Ever since these samples came, back, there’s been botanists that wanted to know what would happen if you grew plants in them,” says Barker, who wasn’t involved in the study. “But everyone knows those precious samples are priceless, and so you can understand why NASA was unwilling to publish them.”
The team planted seeds in tiny pots that each held about a gram of dirt. Four pots were filled with samples returned by Apollo 11, another four with Apollo 12 samples and a final four with dirt from Apollo 17. Another 16 pots were filled with earthly volcanic material used in past experiments to copy moon dirt. All were grown under LED lights in the lab and watered with nutrients.
“Nothing really compared to when we first saw the seedlings as they were coming up in the lunar dirt,” says Anna-Lisa Paul, a plant biologist. “That was a moving experience. We could not speak when we watched the very first plants growing in unique materials.”
Plants grew in all the pots of lunar dirt, but none grew as well as those planted in earthly material. “The healthiest ones were just smaller,” Paul says. The moon-grown plants were tiny. Faced with that, explorers need to do more research to let plants grow strongly on the moon. I believe we will succeed in time.
1. What does the research on plants grown in the lunar dirt show?| A．Growing foods on the moon is necessary. |
| B．Skills are the key to farming on the moon. |
| C．Farming’ on the moon needs many factors. |
| D．Astronauts want to grow food on their own. |
| A．Some plants need planting in special soils. |
| B．Botanists are interested in studying new things. |
| C．It is a selfish action for NASA to keep the secret. |
| D．The samples brought from the moon are valuable. |
| A．It is practical. | B．It is hopeful. |
| C．It only attracts astronauts. | D．It challenges most experts. |
| A．The First Plant Has Been Grown in Moon Dirt |
| B．Astronauts Have Brought Things Worth Spreading |
| C．Botanists Have Found a New Kind of Plant Lately |
| D．Farming on the Moon Has Been Accepted by People |
3 . Many animals depend upon sound to find food, detect predators and communicate with one another. These species understandably suffer when loud motorways cut through their habitats. Some deal with this problem by singing more loudly, some change the timing of their calls to occur when fewer people are driving, others just move to quieter places.
It has always been assumed that noise is a problem unique to animals. But a new study by Ali Akbar Ghotbi-Ravandi, a botanist at Shahid Beheshti University in Tehran, has revealed that plants suffer too.
That plants can be affected indirectly by noise pollution has never been in doubt. Since most flowering species depend upon pollinators and most fruit-bearing species need animals to disperse their seeds, it is obvious that if these animal partners are harmed by noise then their botanical plants will do badly, too. What has remained unknown is whether or not plants themselves suffer directly from noise pollution.
Sounds are pressure waves transmitted through gases, liquids and solids. Scientists have previously predicted that plants may be able to sense these waves as they are struck by them. A number of experiments have confirmed this in recent years — plants attacked with ultrasound in the lab have shown a range of hurtful responses, including the expression of stress-related genes, underdeveloped growth and reduced germination (发芽) of seeds.
Working with a team of colleagues, Dr. Ghotbi-Ravandi grew two species in his lab that are commonly found in urban environments. The plants were grown from seeds and allowed to mature for two months in the same space before they were divided into two groups. One group was exposed to 73 decibels (分贝) of traffic noise recorded from a busy motorway in Tehran for 16 hours a day. The other group was left to grow in silence. After 15 days, samples were taken from the youngest fully expanded leaves on every plant in the experiment and studied.
None of the plants exposed to the traffic noise did well. Analysis of their leaves revealed that all of them were suffering. Harmful chemicals in them are indicators of stress in plants and both were found at much higher levels in the plants exposed to the traffic noise. Most notably, levels of the harmful chemicals in the plants exposed to noise were two to three times what they were in those grown in silence. The findings make it clear that the noise of traffic bothers the plants.
1. What’s the function of the first two paragraphs?| A．To lead in the topic of the passage. |
| B．To prove that only animals suffer from noise. |
| C．To introduce how animals avoid the urban traffic noise. |
| D．To compare the different effects of noise on animals and plants. |
| A．Classify. | B．Spread. | C．Damage. | D．Collect |
| A．Urban traffic noise mainly poses a threat to animals. |
| B．Plants themselves suffer indirectly from noise pollution. |
| C．Plants exposed to the traffic noise bear higher levels of stress. |
| D．Plants that don't need animals for growth will not be influenced by noise. |
4 . The Greenwood fire took its name from the nearby lake where lightning struck on Aug.15, causing a wildfire that burned for weeks. Fueled by drought and wind, its persistence dominated headlines for much of late summer and early fall in Minnesota. When the last flames were finally put out, the northern Minnesota fire had consumed nearly 27,000 acres, countless firefighting resources, and at its worst, the lives that some had built around nearby McDougal Lake. Vast areas of forest were left burned-out, with the black and bare remains of what were once massive pines.
But, despite the destruction left behind, Mother Nature is set to a comeback. When organic matter is burned from the forest floor, seeds dropped by plants and trees begin to take hold, with the sprouting species emerging first. The trees above have died, which sends a chemical signal to the root system that is actually more expansive than just under that tree, and that chemical response encourages those root systems to re-grow. Ten years ago, a fire ripped through 93,000 acres of Minnesota forest in and around the BWCA. Today, that burnt area's rebirth is well underway.
"Here in the Pagami Creek wildfire scar, we have Jack Pine, Red Pine, Black Spruce, Aspen and paper birch-those are our main species, those are the ones that are growing quickly. It's 10 years on, and these trees are 10 to 15 feet tall in many areas," said Kyle Stover from the U.S. Forest Service.
A wildfire kills most things in its path, but despite the flames and intense temperatures, rarely is everything reduced to ashes -and that plays a key role in a forest's regeneration. Just one year after the fire, the survivors dominate the forest, and grasses replace the burnt ground. Wildflowers are abundant bushes and small trees have started to grow, and Jack Pine returned. So, it's an amazing ecological system of creating new forest life when it appears that all is lost, one that has evolved throughout the ages, where fire has always played a vital role.
1. What can we learn about the Greenwood fire?| A．It was a natural occurrence | B．It was caused by drought. |
| C．it gained half-year fame. | D．It took many people's lives. |
| A．Seeding growth is held up. | B．Burnt organic matter hardly functions. |
| C．Root systems spread further and wider | D．Chemicals in the soil are in greater demand. |
| A．They are flammable | B．They are fire-resistant |
| C．They are fire-adapted. | D．They are overgrown. |
| A．A fire. | B．A life | C．A time. | D．A system |
5 . Roughly 100 m farmers in several tropical countries depend on coffee for their livelihoods. Unfortunately for them, and for the many other coffee drinkers around the world, coffee bushes grow best in a rather narrow range of temperatures, so their cultivation is threatened by a changing climate. But a chance discovery by Aaron Davis of the Royal Botanic Gardens, Kew, in Britain, published in Nature Plants, may offer a way out. Dr Davis and his colleagues report that they have tracked down a type of wild coffee which is both pleasant to taste and tolerant of higher temperatures.
The existing coffee market is dominated by Coffea arabica and Coffea canephora. Coffea arabica prefers temperatures of 18-22 °C. Recent work suggests that Coffea canephora does not flourish above 24 °C.
Many other coffee species, indeed, grow in places warmer than those preferred by canephora and arabica. But all were thought to have poorer flavours, smaller beans and lower yields. Dr Davis, however, came across a paper written in 1834 by George Don, a Scottish botanist, which described a species from the lowland hills of Sierra Leone. Don dubbed（给……起绰号）it Coffea stenophylla, and wrote that it had a flavour superior to arabica's.
This piqued Dr Davis's interest, for stenophylla still grows, he discovered, in parts of Guinea, Sierra Leone and Ivory Coast that have temperature ranges between 24 and 26 °C. He and his colleagues also learned that stenophylla was farmed up until the 1920s, after which canephora, which had higher yields, took over. Stenophylla was then gradually forgotten.
That history of previous cultivation did, however, suggest stenophylla was worth looking into. The crucial question was Don's praise for its flavour justified? To find out, Dr Davis arranged a competition involving 18 professional coffee tasters who assessed, in a blind comparison, a set of samples that included stenophylla, two types of arabica and one of canephora.
Stenophylla performed well. It was rated as having higher fruitlike qualities than a Brazilian arabica and an Indonesian canephora, and also a more favourable acidity and more complex flavour profile, though slightly less of these qualities than an Ethiopian arabica. When asked if what they were tasting was arabica, the judges said "yes" 81% for samples of stenophylla, compared with 98% for the arabica from Ethiopia.
These results suggest that Don's report from 1834 is correct. Stenophylla does taste like arabica. And, crucially, it tolerates higher temperatures than either arabica or canephora. The rediscovery of stenophylla's qualities offers hope not only to coffee growers who might otherwise have had their businesses harmed by rising temperatures, but also to the world's caffeine addicts, who need now worry less about the future supply of their drug of choice.
1. Why are coffee yields threatened?| A．The number of coffee drinkers is decreasing. |
| B．Global temperature is rising. |
| C．Less farmers plant coffee bushes. |
| D．Farmers choose other crops for their livelihood. |
| A．Coffea stenophylla was first found in 1834. |
| B．Coffea arabica grows in places warmer than many other coffee species. |
| C．Coffea stenophylla had lower yields than canephora. |
| D．Coffea stenophylla is still favoured by farmers. |
| A．Stenophylla has the same qualities as an Ethiopian arabica |
| B．An Ethiopian arabica tastes like stenophylla |
| C．A Brazilian arabica tastes better than stenophylla |
| D．The flavour of stenophylla is like arabica's |
| A．To explain a study method on coffee species. |
| B．To introduce a new species of coffee. |
| C．To stress the importance of coffee growing. |
| D．To propose a new way to increase coffee crops. |
