1 . 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. |
2 . Increased human activity and climate change have caused a rise of algae (藻类植物) in water bodies around the world—sometimes choking ecosystems of sunlight and oxygen. In more extreme cases, they can produce dangerous poisons that can sicken or kill people and animals. But the plenty of algae could prove crucial as our population rises beyond eight billion people worldwide because algae are crops that don’t need land, freshwater, or fertilizer to fill nutritional gaps.
And even though they are so closely associated with human’s bad impact on Earth, algae could also play vital roles in slowing climate change and helping fight against pollution, viruses, and more. With microplastic pollution documented in almost all habitats related to water, a study showed that algae can help filter microplastics from water. Algae can also filter chemicals that can be used for fertilizer.
Algae can produce more effective biofuel than traditional sources. Rescarchers at a German algae growing facility are already using it to fuel plane. Researchers believe this and other sustainable fuels could reduce carbon released from airplanes by up to 80 percent.
Animal feed containing a kind of red algae reduces harmful methane(甲烷)released from cattle by more than 80 percent. The addition works by changing the environment in a cow’s stomach, stopping the production of methane before it can be released.
Red algae can stop the copies of some viruses, and have been shown to stimulate the body’s immune (免疫的) system and could become a powerful anti-HIV medicine.
In 2019, freshwater algae were launched into space to change the CO2 breathed out 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.
1. What can we know about algae from the first paragraph?| A．Better late than never. | B．Every coin has two sides. |
| C．All is well that ends well. | D．Two heads are better than one. |
| A．They avoid climate change. | B．They absorb pollutants in the air. |
| C．They reduce microplastics in the water. | D．They filter most poisonous chemicals. |
| A．Change animal feed into methane. |
| B．Store carbon released from airplanes. |
| C．Help researchers to create traditional sources. |
| D．Create biofuel and reduce methane in cows’s stomach. |
| A．By helping fight against diseases. | B．By increasing human’s strength. |
| C．By producing more oxygen than other plants. | D．By replacing much food for astronauts. |
3 . Now, a study proves that gardens are more than just a pretty place. The study, by researchers at Illinois State University, demonstrates that such constructed gardens can have a measurable and positive impact on water quality.
Floating gardens are essentially platforms built and wrapped in coconut husks (椰子壳), and filled in with native plantings. As plants grow, they extend their roots into the water. On the North Branch of the Chicago River, non-profit Urban Rivers and its partners are developing a mile-long floating eco-park called the Wild Mile. The re-development of this former industrial canal is Urban Rivers’ important project. As part of the park, floating gardens, attached to shore, are being fixed.
The primary aim of the floating gardens is beautification. But the Illinois State team, from the University’s Department of Geology, Geography, and the Environment, saw an ideal setup for a controlled experiment. “We joined it because it’s the perfect opportunity to see if there’s an influence on water quality,” explains lead author Abigail Heath.
The study is novel: previous studies have explored floating gardens’ influence on water quality over time, primarily in wastewater treatment ponds, but not over space, in moving water. The project also matches well with Urban Rivers’ broader goals. “The city is interested in bettering water quality,” says Phil Nicodemus, Urban Rivers’ Director of Research. “Happily, Illinois State took part in it later.”
Could this small human-made park improve water quality? An average of data collected over the course of the study shows middle but definitive improvement. For example, nitrogen (氮) dropped from 4.69 milligrams per liter in surface water to 4.43 milligrams per liter, a drop of about 1 percent.
“Despite how small this garden was, there was measurable improvement in water quality from upstream to downstream,” notes Heath. She and her colleagues see this as a model for how large floating gardens should be to help improve water in similar settings. “Even this tiny garden makes a difference,” she says.
1. What can be inferred from the second paragraph?| A．The floating gardens are environmentally friendly. |
| B．The floating gardens are fixed everywhere in the eco-park. |
| C．The floating gardens can help fix the former parks. |
| D．The Urban Rivers were once industrial canals. |
| A．To reduce waste water. | B．To attract more visitors to the park. |
| C．To make the surroundings brilliant. | D．To help researchers do the experiment. |
| A．The floating garden. | B．The project. |
| C．The treatment of ponds. | D．The quality of water. |
| A．Floating Gardens: More than Pretty |
| B．The Best Way to Better Water Quality |
| C．A Practical Method of Improving Parks |
| D．Floating Gardens Beautify the City |
4 . For many people, catching a smell of freshly cut grass is a pleasant sign that warmer weather is here to stay. For the grass, however, this scent signals an entirely different story.
The smell we associate with freshly cut grass is actually a chemical SOS, one used by plants to beg nearby creatures to save them from attack. After all, when danger strikes —whether it's gardening equipment or a hungry caterpillar — plants can't lift their roots and run. They must fight where they stand. To protect themselves, plants employ a string of molecular (分子) responses. These chemical communications can be used to poison an enemy, warn surrounding plants of dangers or attract helpful insects to perform needed services.
Clearly, plants can communicate. But does that mean they can feel pain? According to some researchers, plants release gases that are the equivalent of crying out in pain. Using a laser-powered microphone, researchers have picked up sound waves produced by plants releasing gases when cut or injured. Although not audible to the human ear, the secret voices of plants have revealed that cucumbers scream when they are sick, and flowers cry when their leaves are cut.
There's also evidence that plants can hear themselves being eaten. Researches show that plants understand and respond to chewing sounds made by caterpillars dining on them. As soon as the plants hear the noises, they respond with several defense mechanisms.
For some researchers, evidence of these complex communication systems — giving out noises via gas when in pain — signals that plants feel pain. Others argue that there cannot be pain without a brain to register the feeling. Still more scientists infer that plants can exhibit intelligent behavior without possessing a brain or conscious awareness.
As they grow, plants can change their paths to avoid obstacles or reach for support with their tendrils (卷须). This activity comes from a complex biological network distributed through the plants' roots, leaves and stems. This network helps plants reproduce, grow and survive.
1. What does the smell of freshly cut grass signal?| A．Warmer weather. | B．Being poisonous. |
| C．Cry for help. | D．The need of services. |
| A．By giving out gases. | B．By changing the color of their leaves. |
| C．By producing audible sound waves. | D．By sharing it through the root systems. |
| A．Their tendrils. | B．Their biological network. |
| C．Their communication systems. | D．Their conscious awareness. |
| A．Do plants feel pain? | B．How plants protect themselves? |
| C．Do plants communicate? | D．How plants grow and reproduce? |
