Global warming is pushing the number of polar bears to
Polar bears live
Studies show that
“What we’ve shown
The study estimates that, even in a situation
2 . Rivers are very important. Humans rely on them for food and water. But rivers can destroy things, too. They can flood, or rise over their banks, making the water run into the nearby land. Floods can also kill humans and wildlife. However, floods are not always bad. Some ecosystems need them every once in a while.
Flooding can not only drown animals but also destroy habitats. For example, a flood in India in 2012 killed many one-horned rhinos. Flood waters can pick up dirt from riverbanks, which makes the water dirty. Too much dirt will clog rivers and streams, preventing the river from flowing. Sometimes flood waters can carry pollution to the sea and harm marine life. In addition, flood waters can carry disease, including hepatitis A (甲型肝炎) and cholera (霍乱).
However, not everything about floods is bad. Sometimes they bring new life to ecosystems. Flood waters carry nutrients to the nearby land. Over time, the water dries up and leaves behind particles (微粒) of dirt and mud. The particles are called sediment (沉淀物) which can be good due to its ability to improve the dirt and help plants grow. Floods are important to some animals as well. For instance, some animals see floods as a sign that it is time to mate or migrate. Floods leave sediment on river beds where baby fish can grow and carry nutrients for small animals in the water to eat. Moreover, in dry seasons, water might dry up, but floods help refill the wetlands, keeping the ecosystem going.
Floods are a part of nature. They can destroy living things and the environment. But some ecosystems need floods to survive.
1. What’s the possible meaning of the underlined word “clog” in Paragraph 2?| A．Become. | B．Pollute. | C．Block. | D．Develop. |
| A．Nutrients carried by floods can make soil richer. |
| B．Floods make all the animals migrate more easily. |
| C．Tiny fish going with floods feed some animals. |
| D．Floods can improve the dirt and help plants grow. |
| A．The way in which floods feed animals. | B．The benefits of floods to ecosystems. |
| C．An effective means of improving soil. | D．The reason for people’s appreciating floods. |
| A．The Bad Effects of Flooding | B．The Secret of Flooding |
| C．Floods-A Disaster to Humans | D．Floods — A Part of Nature |
The problem that the Li River in Guangxi Zhuang Autonomous Region suffered from severe water pollution was caused by many factors such as many tourists frequently
4 . Small batteries are big problems, but nobody really pays attention to where they end up. Researchers at the Cellulose & Wood Materials Laboratory are working to address this problem. Their new research paper describes a water-activated paper battery developed from environmentally friendly materials that could eventually present a sustainable alternative to the more harmful batteries common in low-power devices.
The paper battery has the same key components as standard batteries but packages them differently. Like a typical chemical battery, it has a positively charged side called a cathode, a negatively charged side called an anode, and a conductive material called an electrolyte (电解质) between the two. A traditional battery’s components are enclosed in plastic and metal; in the new battery, the anode and cathode are inks printed onto the front and back of a piece of paper. That paper is filled with salt, which dissolves (溶解) when the paper is dampened with water. The resulting saltwater solution acts as the electrolyte.
Sustainable materials were a precondition for the researchers, who considered only safe and plentiful ingredients to create their device. “We were fairly confident that we would have something that would work in the end, but developing these materials and ink systems is challenging,” says Gustav Nyström, senior author of the study.
After trying hundreds of formulations for the battery components, the researchers settled on a graphite ink to make the cathode, a zinc ink for the anode, and salt-filled paper to create the electrolyte.
When the paper is dry, the battery is shelf-stable. Add just a couple of drops of water, however, and the salt dissolves, allowing electrons to flow. Once the paper is dampened, the battery activates within 20 seconds. The new battery’s operating performance declines as the paper dries. When the scientists re-wet the paper during testing, the battery regained functionality and lasted an hour before beginning to dry out again.
Although the researchers demonstrated that their battery could power an alarm clock, the paper batteries are unlikely to replace standard ones on store shelves. Nyström envisions a future where these paper batteries could make their way into products within the next two to five years. “The performance that you see on this device, I think, is enough for a lot of other applications already,” he says. It is mostly a matter of increasing production and integrating the batteries into systems such as diagnostic tests and environmental sensors.”
1. How is the paper battery similar to the standard battery?| A．The key components are environmentally friendly. |
| B．They are both packaged in plastic and metal. |
| C．They both have two charged sides and an electrolyte. |
| D．Both batteries can operate for only an hour. |
| A．Heating the salt | B．Charging the electrons |
| C．Drying out the battery | D．Wetting the paper |
| A．major technological breakthrough will be made in the near future |
| B．all home appliances will be powered by paper batteries |
| C．the future for a wide application of paper batteries is not far off |
| D．paper batteries will have longer shelf life than traditional ones |
1. 讲座主题：The World Wildlife Day；
2. 时间、地点及讲座内容。
注意：1. 词数为 80左右；
2. 请按如下格式作答。
Notice
___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________The Student Council
March, 1
6 . Growing up in Mauritius, I love nature. Behind my house, there is a mountain named Le Pouce, where I spent much time
When I was about 10, this started to change. I began learning about the
Gradually, I realized how much humans
Diving plays a big part in my life now, and I work to
Protecting the ocean is very
| A．exploring | B．transforming | C．extending | D．constructing |
| A．shifted | B．appeared | C．stretched | D．stopped |
| A．destroyed | B．surrounded | C．covered | D．represented |
| A．scared | B．excited | C．addicted | D．disappointed |
| A．progress | B．threat | C．opportunity | D．image |
| A．avoiding | B．counting | C．highlighting | D．considering |
| A．then | B．yet | C．thus | D．moreover |
| A．lead | B．follow | C．recognize | D．prevent |
| A．efficiency | B．awareness | C．memory | D．confidence |
| A．paid back | B．adapted to | C．depended on | D．kept up |
| A．mood | B．imagination | C．hobby | D．experience |
| A．turn down | B．hold back | C．add up | D．contribute to |
| A．introduction | B．influence | C．advertisement | D．prediction |
| A．risky | B．impractical | C．shocking | D．crucial |
| A．join | B．respect | C．teach | D．guide |
| A．How to sort out rubbish. |
| B．How to protect the environment. |
| C．How to ensure city safety. |
Over the last decade, China
Recently, a man named Zou Yi,
A strong earthquake made Joseph Cadeau wake up from sleep on Saturday. Cadeau, a teenage boy,
Cadeau was one of at least 12,268 people
Cadeau managed to get out of the rubble
“I received treatment too late, which is why my foot is swollen like that,” said the teenager, pointing at
10 . Off the coast of northeastern Queensland, Australia, near Magnetic Island in Florence Bay, the Great Barrier Reef corals (大堡礁珊瑚) are having a baby boom (激增).
“Every year there are more anrd more coral babies,” says Hillary Smith, an ecologist at ames Cook University in Australia.
That’s thanks to a simple but effective strategy for cleaning the region’s coral reefs: “seaweeding”. Like weeding (给……除杂草) a garden, seaweeding involves pulling big handfuls of large algae (水藻) off reefs and taking them away.
Experts say getting climate change under control is key to keeping the world’s reefs healthy. But meanwhile, local efforts such as seaweeding can help corals grow and reduce the effects of climate change.
The health of coral reefs around the world is dire: By 2050, 95 percent of the world’s coral could experience heat stress, according to a 2020 report by the Global Coral Reef Monitoring Network. Algae is a big problem: Already, algae cover has increased on two-thirds of reefs around the world, and one study published in 2021 showed that half the world’s coral reefs have died since the 1950s. Removing seaweed from reefs requires a great deal of work but is not complex, making it a good project for citizen scientists eager to help restore (恢复) reefs.
When the project first began in 2018, Smith says researchers weren’t sure if removing seaweed would benefit the reef or if removal might have the opposite effect in some way. But now, “It’s all looking really positive for the reef,” she says.
Volunteers are ready and waiting to help near Townsville and at other affected Australian reefs, says the Earthwatch Institute’s Fiona Wilson.“We need lots of willing hands to remove seaweed. It takes weeks of time,”she says. “But obviously recovery of the Great Barrier Reef is a passion for many people, so we draw volunteers.”
1. What contributed to the growth of the Great Barrier Reef corals in Florence Bay?| A．Local efforts to remove seaweed. | B．Reduced effects of climate change. |
| C．Fewer human activities in the region. | D．The use of new restoration technologies. |
| A．Strange. | B．Acceptable. | C．Excellent. | D．Terrible. |
| A．They were hopeful of it. | B．They were excited about it. |
| C．They were uncertain about it. | D．They were uninterested in it. |
| A．It is still a long way off. | B．It is less difficult than thought. |
| C．It will take hard work and skill. | D．It attracts and needs volunteers. |
