Australia's koalas could die out within 30 years unless immediate action is taken to stop the losing in population, according to researchers. They say development, climate change and bushfires have all combined to reduce the number of wild koalas sharply.

    The Australian Koala Foundation said a recent survey showed the population could have dropped by more than half in the past six years. The number of koalas was once estimated to be more than 100,000, but now is as few as 43,000.

    The foundation collected field data from 1,800 sites and 80,000 trees to calculate the numbers. In one area in northern Queensland estimated to have 20,000 koalas a decade ago, a team of eight people could not find a single animal in four days of searching.

    The foundation said besides problems caused by cutting down forests, hotter and drier conditions because of global warming had reduced the nutritional value of their main food, eucalyptus (桉树) leaves, leading to poor nutrition for them. Koalas, which live in the forests in Australia's east and south, are very picky about what types of the leaves they eat.

    Foundation chief Deborah Tabart said: “The koalas are missing everywhere we look. It's really no tree, no me. If you keep cutting down trees you don't have any koalas.”She is hoping the new figures will persuade the government's Threatened Species Steering Committee (TSSC) to list the koala as threatened. But committee chairman Bob Beeton said a decision was not likely recently and the koala's status as one of the country's favorite animals would not be a factor. “There's a number of species which are attractive and people have special feelings towards them. We don't consider that,” Mr Beeton said.

    NASA might be famous for sending rockets up to space quickly. But it will be more famous for making your next holiday come more quickly.

    The space agency is working on a new plane, which could solve the problems of supersonic(超音速的) flight and vastly increase the speed of journeys abroad. If successful, the plane would be able to fly between New York and London in just three hours. And it would reduce the time spent flying other journeys by a half, since it could be used more broadly. Until now, the problem with such planes has been the sonic boom(声爆), made famous by the original Concorde. That happens when a plane reaches supersonic speeds.

    It is a thunderous noise that upsets people on the ground— disturbing animals and even causing physical problems to materials and houses underneath. It was that effect that led Congress to ban such planes from being used over the US land, a decision that in turn was responsible for Concorde's failing to be commercially used.

    In view of the problem, the space agency has developed a new technology and tried it out in wind tunnels, and now believes that it could be put to commercial use. That plane will fly as high as 55,000 feet—far higher than normal planes—and make a sound of only 60 decibels. That's far less than 90 decibels thrown out by normal planes, and is roughly in line with a car on the motorway or a busy restaurant.

    “As long as we can get endorsement from the general public, the plane will probably be something that's acceptable,” said Peter Coen, project manager for NASA's commercial supersonic research team, in a new Bloomberg report. “If we get approved, we will have the full-sized version of the plane tried out and the plane will be put into use.”

    Many of us think, wrongly, that the moon doesn't change. For example, the Tang Dynasty poet Zhang Ruoxu once wrote that "Generations have come and passed away; From year to year the moons took alike, old and new."

    However, a new study published in the journal Nature Geoscience shows that the moon is in fact slowly shrinking over time. For the study, a group of US scientists examined and analyzed thousands of photographs taken by the NASA orbiter Lunar Reconnaissance Orbiter Camera (月球勘测轨道飞行器照相机) . They found that there were lots of faults (断层) on the surface of the moon. These faults were formed by recent movement on the moon.

    According to NASA, the moon is made up of pieces of rocks with a hot core (核) .The moon continued to expand as it was born. But in this process, it released energy and cooled down. Then it began to shrink, in a way comparable to the shrinking of a grape into a raisin (葡萄干) . Over the past several hundred million years, it has become 46 meters "skinnier". But due to its hard and rocky crust (外壳) . the moon's surface continues to push up, "Some of these quakes can be fairly strong around five on the Richter scale (里氏震级) ," said Thomas Watters, a senior scientist at the Smithsonian's National Air and Space Museum in the US.

    But does that mean the moon is a dangerous place that human shouldn't try to explore and live on in the future? Maybe not, reported the Telegraph, "This isn't anything to worry about. The moon may be shrinking, but not by much. It's not going anywhere," Watters comforted us.

    The new discovery proves that the idea that the moon is a dead, boring place is wrong. "We have been to the moon and we've done some great science, but there is still a lot we don't know. The moon is shrinking ­ we didn't really realize that until recently. It's a much more active and interesting place than we thought and we should explore that," NASA scientist Nathan Williams said.

Earthworms don't move fast. But humans can accelerate the worms' spread. Fishermen often use invasive(蔓延性的) earthworms to catch fish. Many have introduced invasive earthworms to rivers, streams and lakes previously unexposed to these animals. Gardeners who use earthworms to make their soil rich may unknowingly introduce invasive ones. The worms even give rides in the mud on wheels, potted plants and road materials shipped around the nation.

But they're not everywhere yet. In the Great Lakes region, "20 percent of the land is earthworm-free," says Cindy Hale, a research biologist. Of the remaining 80 percent of land, half of the land has fewer than two earthworm species-meaning there isn't yet too much impact on the ecosystem, she explains. For these regions, she says, now is the time to take action. According to Hale, educating the public, especially fishermen, is one approach to stopping the spread of invasive earthworms. Identifying which lands are currently earthworm-free is another.

Ryan Huefimeier, a program coordinator for Great Lakes Wom Watch, has been working on a model that will help create large maps of areas with minimal(最小的) or no damage from earthworms. Ultimately, landowners can use it to identify earthworm activity on their property. once identified, lands with minimal or no earthworm damage should be protected.

But scientists suspect that once invasive earthworms arrive they can't be removed. And even if all could be, affected forests might never return to the way they were. "It's very much a story of learning to live with them," concludes Lee Frelich of the University of Minnesota's Center for Forest Ecology.

Forest ecologists have called earthworms "ecosystem engineers" because they can change or create habitats that otherwise would not be present. Whether this is a good thing depends on the situation.

"What the earthworms do and how we value it is what really matters." said Hale. "In one place-farm fields or gardens-we really like European earthworms and what they do, so we consider them good. In native hardwood forests, we really don't like what they do-so we consider them bad. You really have to understand how an organism(微生物) affects an ecosystem. Things aren't black and white."

第三部分，英语知识运用，

I was born in a poor village in Uganda. I spent the 1 days of my childhood there. My mother died when I was born. My father never cared about me, which 2 me to leave when I was ten. For the next three years, I helped people do something and they provided me with shelter and food 3 . Luckily, a 4 family paid for me to go to school. For the first time after leaving home, I felt 5 . Then, I attended school and got a job. I always 6 to help children in need. Yet I 7 felt I could do something more.

In 2016, I got passed to be a foster (收养) parent. By the end of 2019, ten kids had filled my house. In 2020, I got a call from a center for 8 children. When asked if I could take Anthony, I 9 it because ten kids were all I could do with. 10 , I was talked into taking Anthony just for the weekend. I didn't ask about his situation 11 .

Anthony arrived that night, "Can I call you Dad?" he asked.

"No." I needed to keep my 12 .

Monday morning a worker in the center came to 13 Anthony. From their talk, I learned he had been 14 three times, but nobody would take him in.

Looking at Anthony, I saw something that made me think of the 15 boy I had once been. "I'll take him in," I said.

At a snow park in Zhangiakou, Hebei, Chinese teenage snowboarder Su Yiming won a silver in the men's snowboarding competition on February 7, 2022. It was the first time that a Chinese snow boarder had ever competed in this event at any Olympics. 

Su was introduced to snowboarding at the age of 4 by his parents who were both snowboarding fans. Su fell in love with the sport the first time they took him to a ski center. Later he kept on practicing after class. To save up more time for snowboarding, he would get up at 5 a. m. and finish his homework early. Su just saw snowboarding as a hobby in the beginning. However, on July 31, 2015, when he knew that 2022 Winter Olympics would be held in Beijing, his mind tuned to professional (职业性的) competition. He dreamed of joining in the Winter Olympics. And he decided to go professional. 

In 2018. Su became a member of China's national snowboarding team. In 2020 and 2021, he took home gold medals (奖牌) in all national competitions. In January 2021, he became the first Chinese male snowboarder to finish the Cab 1800-one of the most difficult snowboarding skills. 

Behind his success is Su's hard work. He has made full use of every chance to train more. Usually he arrived at the training center earlier than his teammates. In that way, he could practice more. He even broke several snowboards in one week because of heavy training.