1 . Four surprising ways algae (藻类) are driving innovation
Algae can be a double-edged sword. Increased human activity and climate change have caused explosions of algae populations in water bodies around the world sometimes choking entire ecosystems of sunlight and oxygen. Even though they are so closely associated with humanity’s negative impact on Earth, algae could also play key roles in helping fight pollution, viruses, and more.
Filtering (过滤) water.
With microplastic pollution documented in almost all water bodies, a recent study shows that through absorption, algae can help filter microplastics out of water.
Fueling air travel.
Fighting viruses.
Red algae can prevent the replication (复制) of some viruses, including COVID-19, according to a 2020 study.
In 2019, freshwater algae were launched into space to turn the carbon dioxide exhaled (呼出) by astronauts on the International Space Station into oxygen. Since algae are also high in protein, they could replace up to 30 percent of astronaut food in the future.
| A．Making space food more nutritious. |
| B．Making long-term space travel possible. |
| C．These are several ways algae are solving modern problems. |
| D．Some algae can also filter chemicals that can be used in fertilizers. |
| E．Brown algae have been shown to stimulate the body’s immune system. |
| F．Algae can produce more effective biofuels than traditional sources like soybeans. |
| G．It aims to harvest algae for energy while keeping the environment pollution-free. |
1. How does the woman feel at first?
| A．Amused. | B．Curious. | C．Excited. |
| A．Flowers. | B．Trees. | C．Mushrooms. |
| A．Common. | B．Special. | C．Interesting. |
| A．On Thursday. | B．On Friday. | C．On Saturday. |
1. What is Akira Miyawaki?
| A．A scientist. | B．A professor. | C．An officer. |
| A．Producing more oxygen. |
| B．Dealing with climate change. |
| C．Attracting different kinds of animals. |
| A．It helped communities build 100 forests. |
| B．It taught people to grow their own mini forests. |
| C．It educated kids about tiny forests. |
| A．Mini forests are inspired by a French scientist. |
| B．Miyawaki has planted more than 1,000 forests in Japan. |
| C．Planting mini forests has become popular in Europe. |
4 . Common water plant could provide a green energy source. Scientists have figured out how to get large amounts of oil from duckweed, one of nature’s fastest-growing water plants. Transferring such plant oil into biodiesel (生物柴油) for transportation and heating could be a big part of a more sustainable future.
For a new study, researchers genetically engineered duckweed plants to produce seven times more oil per acre than soybeans. John Shanklin, a biochemist says further research could double the engineered duckweed’s oil output in the next few years.
Unlike fossil fuels, which form underground, biofuels can be refreshed faster than they are used. Fuels made from new and used vegetable oils, animal fat and seaweed can have a lower carbon footprint than fossil fuels do, but there has been a recent negative view against them. This is partly because so many crops now go into energy production rather than food; biofuels take up more than 100 million acres of the world’s agricultural land.
Duckweed, common on every continent but Antarctica, is among the world’s most productive plants, and the researchers suggest it could be a game-changing renewable energy source for three key reasons. First, it grows readily in water, so it wouldn’t compete with food crops for agricultural land. Second, duckweed can grow fast in agricultural pollution released into the water. Third, Shanklin and his team found a way to avoid a major biotechnological barrier: For the new study, Shanklin says, the researchers added an oil-producing gene, “turning it on like a light switch”by introducing a particular molecule (分子) only when the plant had finished growing. Shanklin says, “If it replicates (复制) in other species-and there’s no reason to think that it would not — this can solve one of our biggest issues, which is how we can make more oil in more plants without negatively affecting growth.”
To expand production to industrial levels, scientists will need to design and produce large-scale bases for growing engineered plants and obtaining oil — a challenge, Shanklin says, because duckweed is a non-mainstream crop without much existing infrastructure (基础设施).
1. What can people get from duckweed firsthand?| A．Plant oil. | B．Stable biodiesel. |
| C．Sustainable water. | D．Natural heat. |
| A．Options for renewable energy. |
| B．Reasons for engineering genes. |
| C．The potential of revolutionary energy source. |
| D．The approach to avoiding agricultural pollution. |
| A．Industrial levels. | B．Unique design. |
| C．Academic research. | D．Basic facilities. |
| A．Duckweed Power | B．Duckweed Production |
| C．Genetic Engineering | D．Genetic Testing |
1. What are the good seeds confirmed by?
| A．Containers. | B．X-rays. | C．Freezers. |
| A．To be preserved for long. |
| B．To tackle climate change. |
| C．To safeguard food supply. |
| A．Where seeds are stored. |
| B．How the seed bank works. |
| C．Why seed banks are important. |
6 . Bred to be more sweeter, today’s cherries, bananas and apples taste different than they used — to but not necessarily better. Among fruit farmers, the word “quality” is now routinely used as a standard for “high in sugar”, though firmness, color and size are also considerations. In a recent study about ways to enhance the sweetness of fruit using “molecular (分子的) approaches”, a group of plant scientists wrote that, in general, the sugar content of many fruits are now higher than before owing to continuous selection and breeding. Modern apple varieties, the scientists stressed, were on average sweeter than older ones.
The sweetness of fruit depends not just on how it is bred but also on growing conditions, yield and harvest. The lead researcher, Sugiura, said, “If you could taste an apple harvested 30 years ago, you would feel the difference.” He believed that modern apples are picked so early that even if they are bred for sweetness, they often don’t develop their full character. The fragrance (香味) never develops in fruit that is harvested too early.
Jim Cooper, an apple farmer in England, is regretful to admit the fact that many people will never taste the “strawberry hint” in a really ripe Pearmain, a type of heritage apple. In a way, the rise of consistently sweeter fruit in our lifetimes has been a victory of plant breeding. After all, it’s a rare person who would seek out bitter grapes if they could have sweet ones instead.
But the sweetness of modern fruit is not without its problems, especially for people with diabetes (糖尿病), who have to reduce their intake of higher-sugar fruits. Fruit that is bred sweeter also tends to be lower in the chemicals that make it healthy. Considering health, maybe the real problem with modern fruit is that it has become yet another sweet thing in a world with sugar. Even grapefruits, which used to be quite bitter, are sometimes now as sweet as oranges. If you’ve never tasted a sour cherry, how can you fully appreciate a sweet one?
1. In what aspect is many fruits different from before?| A．Sugar content. | B．Soft skin. | C．Bright color. | D．High yield. |
| A．They are bred too early. | B．They taste so sweet. |
| C．They are losing a good flavor. | D．They need a higher yield. |
| A．Favorable. | B．Critical. | C．Ambiguous. | D．Indifferent. |
| A．It’s a wise choice to breed fruits for sweetness. |
| B．Breeding sweet fruits improves the quality of fruits. |
| C．Some fruits like grapes and cherries taste the same. |
| D．The sweetness of fruits will cause health issues. |
7 . On the streets of Manhattan and Washington, D. C., in neighborhoods in Seoul and parks in Paris, ginkgo (银杏) trees are losing their leaves in reaction to the first gust of cold winter air. This leaf drop, gradual at first, and then sudden, carpets streets with golden, fan-shaped leaves. Scientists are documenting evidence of the event happening later and later, a possible indication of climate change. But the story of ginkgos is not the familiar one of human carelessness with nature.
Thanks to fossils found in North Dakota, scientists found a ginkgo has genetically similar ancestors dating back 170 million years to the Jurassic Period. “It almost went extinct. Then humans rescued it and spread it around the world. It’s such a great evolutionary (进化) and cultural story,” says Peter Crane, a ginkgo expert.
One theory for the decline of the ginkgo species began 130 million years ago, when flowering plants began spreading. They grew faster and attracted more pollinators (传粉者) than ginkgos. “It’s possible that ginkgos were elbowed out of the way,” says Crane. Already competing to survive, ginkgos began to disappear during a time of global cooling that began around 66 million years ago. By the time the last ice age ended 11,000 years ago, the remaining survivors were found in China.
Ginkgo trees are smelly. “My guess is that they were eaten by animals that liked smelly things. They then passed through their body and grew.” Crane says. Those same seeds may have helped ginkgo find favor with humans 1,000 years ago. Once cleaned of their outer layer, ginkgo seeds are safe to eat. It’s then, when the trees had long since disappeared elsewhere, that people in China may have begun planting them and eating their seeds. Then gradually ginkgos spread across the world. Now it’s seemingly naturally resistant to insects and high levels of air pollution.
Crane isn’t worried about its future, though: The popularity of the species will help it survive. “Though its status in the wild may be difficult to access, it’s a plant that’s unlikely to ever go extinct,” he says.
1. What may have caused the further delay of ginkgo’s leaf drop?| A．The colder weather in winter. |
| B．The protection from city councils. |
| C．The global warming phenomenon. |
| D．The careless interaction with humans. |
| A．The reasons why ginkgos almost died out. |
| B．The advantages of ginkgos over other plants. |
| C．The theories of experts for multiplying ginkgos. |
| D．The competition between various flowering plants. |
| A．Their eatable seeds. | B．Their unpleasant smell. |
| C．The natural evolution. | D．The careful planting. |
| A．Worried. | B．Optimistic. | C．Uncertain. | D．Hopeless. |
8 . Plant biologists have found a way that may enable poor farmers to do away with the need to purchase expensive hybrid seeds every year. Researchers at the University of California report that they have solved a long-standing problem of hybrid seeds by making exact clones of the hybrid plants from seeds.
For long, many crops have been grown from high-yielding, anti-disease or climate-tolerant hybrid seeds. But the seeds of hybrid crops do not produce plants with the same qualities during reproduction and hence farmers cannot save the seeds for the next growing season. They end up paying for new hybrid seeds each sowing season. The discovery, long sought by plant researchers, could make it easier to grow desirable high-yielding crops and make them available to the world’s farmers. Farmers could thus replant seeds from their own hybrid plants and enjoy the benefits of high production year after year, the scientists report.
While the discovery would help farmers, it would also impact the commercial interest of the hybrid seed industry. Siddiq, a former Deputy Director General in the Crop Science Division of the ICAR, said at first sight, this might seem like a setback for hybrid seed companies but there would be plenty of things they can still do. “Rice is grown over such a vast climatic and geographical range that specialized hybrids would have to be developed for each region,” he said. The companies, he said, would continue to improve their hybrids. “It will be interesting to see how all this plays out in the years to come.”
Currently, the high costs of producing hybrid seeds are a major barrier to farmers in developing countries, especially South Asia and Africa. Siddiq said if efficiently used, this method could potentially be a game-changer for poor farmers, who would need to purchase hybrid seeds just once and plant the progeny(后代) seeds from their own harvest in the following seasons.
1. What problem do the researchers aim to solve?| A．Farmers’ income. | B．Farmers’ costs. |
| C．Hybrid seeds’ cloning. | D．Hybrid seeds’ climate tolerance. |
| A．They have a pretty long growth cycle. |
| B．They tend to be affected by various diseases. |
| C．They have stricter requirements for sowing time. |
| D．They fail to reproduce plants with the same quality. |
| A．Hopeful. | B．Concerned. | C．Doubtful. | D．Anxious. |
| A．The future of the hybrid seed industry. |
| B．The drawback of cloning hybrid seeds. |
| C．A method of cloning hybrid plants from their seeds. |
| D．A means of promoting the specialized hybrid seeds. |
9 . The San Francisco-based company, called Living Carbon, has created poplar (杨树) trees that are genetically engineered (改变基因结构) to grow larger and suck up more carbon dioxide from the atmosphere than standard trees do. In February, workers planted rows of these poplars in southern Georgia. The company intends to plant 4 to 5 millions trees by the middle of next year, which they say will help with the worsening climate crisis.
When plants photosynthesize (进行光合作用), they convert carbon into sugar and nutrients that are eventually consumed by all living organisms. But they also produce a harmful byproduct, which must be broken down during the energy-intensive process of photorespiration (光呼吸), said Yumin Tao, the company’s vice president of biotechnology.
“This is not only wastes energy but also loses much fixed carbon in the form of CO2, which gets released into the air again,” Tao added. “It’s a wasteful process many plants do.” Living Carbon has reduced photorespiration in its poplars, instead channeling the energy into growth, he says.
The trees have three genes inserted to achieve this, including one from squash and one from green algae. But the company has yet to show its modified trees can capture more carbon in a real — world setting. Its only publicly available data comes from a study in a greenhouse that lasted for only a few months and has yet to be peer reviewed. “Their claims seen bold based on very limited real-world data,” says Andrew Newhouse, a conservation biologist at the SUNY College of Environmental Science and Forestry.
Still, the study reported the modified poplars grew as much as 53% larger in five months compared to the unmodified ones, capturing 27% more carbon dioxide. Now, the company hopes its other field trials in locations like Oregon and Pennsylvania will show similar successes. It’s currently focused on planting on private lands, where fewer roadblocks exist.
“We specially focus on land where trees otherwise wouldn’t be planted, like abandoned mine lands-areas where there isn’t an existing, rich ecosystem that’s allowing for a large amount of carbon removal right now,” says Maddie Hall, Living Carbon’s CEO.
1. Why does the company want to plant genetically modified poplars?| A．To help with the worsening climate crisis. |
| B．To better study them to gain more accurate data. |
| C．To replace ordinary poplars with genetically modified poplars. |
| D．To find suitable places for genetically modified poplars to grow. |
| A．Disapproving. | B．Ambiguous. | C．Skeptical. | D．Supportive. |
| A．They are very resistant to carbon. | B．They have a growth advantage. |
| C．They have two genes inserted. | D．They photosynthesize even faster. |
| A．A Company Is Trying to Engineer Trees Genetically |
| B．Poplar Trees Might Be Planted All Around the World |
| C．Genetically Modified Trees Are Taking Root to capture Carbon |
| D．Research Is Being Conducted to Use Trees to Remove CO2 |
1. What makes potted roses easier to plant?
| A．Lower nutrition requirement. |
| B．Stronger cold resistance. |
| C．Better root development. |
| A．They need less soil. |
| B．They are easier to transport. |
| C．Their planting time is fixed. |
| A．Damp condition. | B．Heavy sunshine. | C．Continuous watering. |
| A．Types of roses. | B．Ways of rose packing. | C．Tips on rose growing. |
