1 . 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 |
2 . Yellow flower carpeted fields are a sure sign of summer. In Denmark alone, more than 200,000 hectares of rapeseed (油菜籽) are planted every year. But until now, the plant has only been used for oil and animal food, as it is both bitter and unsafe for human consumption.
To protect themselves, the rapeseed plants produce a group of substances (物质) called glucosinolates (硫苷), which give the plants a strong and bitter taste that scares off insects and disease. As a result rapeseed is unhealthy to eat and the rapeseed cake, which is the remains of the seeds after the oil has been squeezed out, has only been used as feed for pigs and chickens, despite its 30 — 40 percent protein content.
Now, researchers from the University of Copenhagen have discovered the three proteins that help to store the bitter substances in seeds of thale cress (阿拉伯芥), a plant closely related to the rapeseed. The new knowledge makes it possible to prevent the accumulation (积聚) of these substances in the seed by removing the proteins through “transport engineering” technology. In doing so, the defensive substances remain in all other parts of the plant, allowing it to continue to defend itself.
So far, the researchers have shown that their method works in thale cress. “The next task is to apply our method to the closely related rapeseed plant, which we are now working on,” says Professor Halkier, leader of the research.
“Half of plant proteins in the EU come from rapeseed. The climate crisis demands that we reduce meat consumption and eat more plants, which is where rapeseed has great potential as a new source of plant protein. Our latest research results bring us a step closer to making full use of rapeseed,” says Professor Halkier.
1. What is the function of paragraph 2?| A．To state the reason. | B．To offer the solution. |
| C．To give an example. | D．To introduce the topic. |
| A．By selecting better seeds. | B．By removing the three proteins. |
| C．By increasing sweet tastes. | D．By storing defensive substances. |
| A．Researchers’ efforts to better the taste. |
| B．Researchers’ progress in their experiment. |
| C．Rapeseed’s role in relieving climate crisis. |
| D．Rapeseed’s potential as a new protein source. |
| A．Harmful proteins discovered in rapeseed |
| B．Rapeseed widely used as oil and animal food |
| C．Researchers closer to making rapeseed safe food |
| D．New plant protein in rapeseed finally uncovered |
3 . Think of a seed buried in a pot. It’s dark down there in the potting soil. There’s no light, no sunshine. So how does it know which way is up and which way is down? It does know. Seeds send shoots up towards the sky, and roots the other way. Darkness doesn't confuse them. Somehow, they get it right.
More surprisingly, if you turn a seedling(秧苗) or a whole bunch of seedlings upside down, as Thomas Andrew Knight of the Royal Society did around 200 years ago, the tips and roots of the plant will sense, “Hey, I’m upside down. Look! I will turn my way to the right direction and do a U- turn.”
How do they know? According to botanist Daniel Chamovitz, Thomas Knight about 200 years ago guessed that plants must sense gravity. Knight proved it with a crazy experiment involving a spinning plate.
He attached a bunch of plant seedlings onto a disc. The plate was then turned by a water wheel powered by a local stream at a speed of 15 revolutions(旋转) per minute for several days.
If you have been at an amusement park in a spinning teacup, you know that because of centrifugal force(离心力) you get pushed away from the center of the spinning object towards the outside.
Knight wondered, would the plants respond to the centrifugal pull of gravity and point their roots to the outside of the spinning plate? When he looked, that's what they'd done. Every plant on the disc had responded to the pull of gravity, and pointed its roots to the outside. The roots pointed out, and the shoots pointed in. So Thomas Knight proved that plants can and do sense the pull.
1. How does the author write about the young seedling in Paragraph 2?| A．By describing vividly. | B．By giving examples. |
| C．By telling stories | D．By asking questions |
| A．Soil. | B．Sunshine. | C．Darkness. | D．Gravity. |
| A．Plants have their own desires | B．Plans can grow quickly by doing a U-turn |
| C．Speed influences plants' growing | D．Plans can feel the centrifugal pull |
| A．In a book review | B．In a lifestyle magazine |
| C．In a scientific report | D．In an official document |
4 . New research has revealed something amazing: it appears that plants can communicate after all.
It has been known for some time that plants use chemicals to communicate with each other. This happens when a plant, say a bean plant, gets attacked by insects. The plant releases tiny amounts of chemicals from the leaves that are being eaten. This is like a warning, or a call for help: “I’m being attacked!” When another bean plant detects the chemicals from its injured neighbour, it starts to release its own, different chemicals. Some of these chemicals drive insects away. Others attract insects—the wasps (黄蜂)! The wasps kill the insects that are eating the bean plants. Scientists hope tolearn more about this plant warning system, so that we can use it to grow crops without pesticides.
More surprisingly, plants also use sound to communicate. People can’t hear these sounds, but plants are making them. Some plants make noises with their roots. Con and chilli plants do this. They also “listen” to the noises from other plants. A chilli plant can tell if a neighbouring plant is helpful, or unfriendly. Some trees make clicking noises when there is not enough water, indicating drought is arriving.
Most surprisingly of all, plants have an amazing system of communication that can link nearly every plant in a forest. Scientists call this system the “wood wide web”. It is in some ways similar to the Internet we use. While the Intenet is a worldwide network of computers linked by cables and satellites, the wood wide web is linked underground by fungi (真菌).This fungal network links the roots of different plants to each other. Using the wood wide web, plants can share information and even food with each other. For example,some pine trees can send food to smaller pine trees to help them grow. But just like our own Internet, the wood wide web has its own version of “cyber crime”. Plants can steal food from each other, or spread poisons to attack other plants. Perhaps one day scientists will learn how to create a “firewall” to help prevent these attacks within the wood wide web.
Scientists are learning more every day about the secret ways in which plants talk to each other. Who knows? Maybe one day we will know enough about plant communication to be able to “talk” with them ourselves.
1. What can we infer from paragraph 2 and 3?| A．A bean plant may release its own different chemicals to drive insects away. |
| B．A bean plant can only attract wasps to kill the harmful insects. |
| C．Scientists have learned more about this plant warning system. |
| D．Most plants can make noises and listen to noises. |
| A．The “wood wide web” is in some ways similar to the Internet we use. |
| B．The “wood wide web” has its own version of “cyber crime”. |
| C．Plants have an amazing system of communication that can nearly cover a forest. |
| D．Scientists will create a “firewall” to protect the wood wide web from attacks. |
| A．Worried. | B．Uninterested. | C．Optimistic. | D．Pessimistic. |
| A．The secret language of plants |
| B．The benefits of plants’ talking |
| C．How plants communicate with each other |
| D．How plants communicate with people |
5 . In the near future IOT(Internet of 'Things)will drive huge innovation(革新)in the way our food is grown. Plants will have a "voice", not a human voice , but a voice based on data that can tell people, computers, and machines when , for example, they are thirsty, or need more sun, medicine, etc.
Take vertical(垂直的)farms for example. Farming is moving indoors where the growth of plants can be monitored and controlled. The facilities are built vertically, so growing areas can be put in piles. This greatly reduces the amount of land needed for farming.
From an IOT point of view, vertical farms are connected in two ways. First, small sensors(传感器)in the soil or connected to plants tell a control system exactly how much light, water, and nutrients are needed to grow the healthiest crops. Sensors will also tell vertical farmers when crops are nearing their peak for harvesting at just the right time to make sure it's still fresh when it reaches its final destination.
Second, vertical farms will be connected to other networks and information systems, including databases that track local demand. For example, local restaurants may input when they need fresh food supplies. And vertical farmers could get that information so they know which crops to grow in what quantities. This type of IOT system would have been unimaginable a generation ago.
Today, vertical farms are being experimented. Yet, the numbers point to a bright future for the industry, especially as the world's population continues to grow. For example, Green Sense Farms in Chicago is able to harvest crops 26 times a year using 85 percent less energy, one-tenth the water, and no pesticides. A side benefit of lower energy use is lower CO, output of two tons per month, with the added benefit of creating 46 pounds of oxygen every day.
1. How do sensors attached to plants work?| A．By recording farmers harvesting crops. |
| B．By monitoring farmers working in their field. |
| C．By passing information on to a control system |
| D．By analyzing information to preserve crops. |
| A．Expand the output of crops. | B．Move restaurants onto farms. |
| C．Determine the needs of farmers. | D．Match supply with demand. |
| A．Hopeful. | B．Unconcerned. |
| C．Negative | D．Doubtful, |
| A．Voice machines help plants speak up |
| B．Farmers are all turning to vertical farming. |
| C．Vertical farms driven by IOT are a future for agriculture. |
| D．IOT has brought great innovation to our future life. |
6 . California has lost half its big trees since the 1930s, according to a study to be published Tuesday and climate change seems to be a major factor(因素).
The number of trees larger than two feet across has declined by 50 percent on more than 46, 000 square miles of California forests, the new study finds. No area was spared or unaffected, from the foggy northern coast to the Sierra Nevada Mountains to the San Gabriels above Los Angeles. In the Sierra high country, the number of big trees has fallen by more than 55 percent; in parts of southern California the decline was nearly 75 percent.
Many factors contributed to the decline, said Patrick McIntyre, an ecologist who was the lead author of the study. Woodcutters targeted big trees. Housing development pushed into the woods. Aggressive wildfire control has left California forests crowded with small trees that compete with big trees for resources(资源).
But in comparing a study of California forests done in the 1920s and 1930s with another one between 2001 and 2010, McIntyre and his colleagues documented a widespread death of big trees that was evident even in wildlands protected from woodcutting or development.
The loss of big trees was greatest in areas where trees had suffered the greatest water shortage. The researchers figured out water stress with a computer model that calculated how much water trees were getting in comparison with how much they needed, taking into account such things as rainfall, air temperature, dampness of soil, and the timing of snowmelt(融雪).
Since the 1930s, McIntyre said, the biggest factors driving up water stress in the state have been rising temperatures, which cause trees to lose more water to the air, and earlier snowmelt, which reduces the water supply available to trees during the dry season.
1. What is the second paragraph mainly about?| A．The seriousness of big-tree loss in California. |
| B．The increasing variety of California big trees. |
| C．The distribution of big trees in California forests. |
| D．The influence of farming on big trees in California. |
| A．Ecological studies of forests. |
| B．Banning woodcutting. |
| C．Limiting housing development. |
| D．Fire control measures. |
| A．Inadequate snowmelt. | B．A longer dry season. |
| C．A warmer climate. | D．Dampness of the air. |
| A．California’s Forests: Where Have All the Big Trees Gone? |
| B．Cutting of Big Trees to Be Prohibited in California Soon |
| C．Why Are the Big Trees Important to California Forests? |
| D．Patrick McIntyre: Grow More Big Trees in California |
