1 . The most beloved bird in history may very well have been a 29-year-old pigeon by the name of Martha. It was the early 1900s, and Martha was at the height of her fame. Perched on her humble roost at the Cincinnati Zoo, she was an object of fascination to the thousands of visitors who lined up just to catch a glimpse. Martha may not have looked the part of an animal celebrity, but she was hardly average—in fact, she was the very definition of one of a kind. After the death of her companion George in 1910, Martha had become the world’s last-living passenger pigeon.

There was a time not long before when her kind accounted for more than a quarter of the birds in North America and may have been the most abundant bird species on the planet. Passenger pigeons used to travel at 60 miles an hour in flocks a mile wide and 300 miles long. Witnesses compared them to a train rumbling through a tunnel.

Ironically, the passenger pigeons’ very abundance may have spelled their doom. An agricultural pest and reliable source of protein, they became easy targets for hunters who killed them in the tens of thousands. In a matter of decades, a bird that once numbered in the billions was reduced to a few, and then, eventually, to one.

Martha, who’d grown up in captivity, had no offspring of her own. At 1 p.m. on September 1, 1914, Martha fell from her perch, never to rise again—one of the rare occasions in which historians could identify the exact moment of a species’ extinction.

Of course, the real tragedy was that the loss of the passenger pigeon was neither surprising nor unique. For as long as the Earth has sustained life, it has also seen the permanent disappearance of life forms, the dinosaurs being a particularly extreme example. But Martha’s high-profile death trained national attention on an alarming new trend. Close to a thousand animal species alone have died off in the last 500 years, and the trend is only getting worse.

2 . South Baltimore is often thought of as a place to avoid—folks are taught to be careful of it. There was a mass shooting this past July, and another in early September.

“People think Curtis Bay is a dangerous place. It’s not. It’s just we’re surrounded by dangerous things,” says Taysia Thompson, 17.

Taysia, is one of the Free Your Voice members, a group of student activists fighting against a very different kind of danger in their neighborhood: air pollution and climate change. Now, the focus of their movement is the mountains of coal. Coal releases a fine, black dust small enough to get into people’s lungs. It makes respiratory (呼吸的) diseases worse, or can even cause disease and premature death. And there are the greenhouse gas emissions after the coal is burned.

The teens of Free Your Voice are taking on a big opponent: the massive goods transportation company CSX, which transported more than 8 million tons of coal through South Baltimore in 2021. The goal is to eventually get the state regulators to deny the permit that CSX needs to operate, or at least require the company to enclose all the coal, or at the very least put water onto all of it so there’s less dust blowing around.

This past summer, Taysia and three other students spent their time gathering evidence to try and get the coal pollution out of their neighborhood. They used sticky paper to gather samples of dust from all over the neighborhood to prove that the dust is from coal. They are also sending dust samples to a scientist in California, who uses an electron microscope to compare the dust that’s in this neighborhood to samples from the piles of coal at the terminal in South Baltimore to see if it matches.

The students now have support from their community. But the responses from officials have not been very satisfying. “Everyone is just breathing the air. And we will keep fighting.” says Taysia.

Xi’an, an ancient capital of China, has secured a place among the most popular     1     (destination) for the enchanting appeal. While     2     (it) historical and cultural landmarks awe visitors, it is the varied, mouthwatering selection of snacks that     3     (true) captivates their hearts.

With its strategic location along the Silk Road, Xi’an is a melting pot of cuisine influences from far and wide, and its history of growing wheat     4     (bring) the creation of a display of flour-based dishes, with noodles taking center stage.

From the iconic biangbiang noodles to the inviting oil-splashed noodles, Xi’an’s noodle scene is a     5     (delight) journey through flavors and textures. Biangbiang noodles, are named for the “biang-ing” sound the noodles are said to make when     6     (beat) on the table as they are being formed. While the appeal of biangbiang noodles is     7     they are wide and hand-pulled, their toppings with tasty ingredients are also a highlight. Another iconic snack, roujiamo, is often referred to     8     the “Chinese hamburger”. This sandwich-like delight has a lengthy history     9     (date) back approximately 2,400 years.

Whatever you’d like to experience in Xi’an, you’ll not only have     10     taste delight, but be amazed by the wisdom of our ancestors throughout history.

5 . Why Are Tigers Orange?

The colors of an animal serve lots of different purposes — for instance, to help them hide into surroundings and escape from being noticed by preys (猎物). For tigers, their ability to be invisible will just decide whether they catch dinner or go hungry.     1    

As for humans, orange is a color used for items that need to stand out, like traffic lights and safety vests. That’s because we have what’s called trichromatic color vision, which differentiate three types of color: blue, green and red.     2     But most other mammals, including dogs, horses and deer, have dichromatic (二色的) color vision for only two colors: blue and green. Humans who get information only of blue and green are considered color-blind, and can’t distinguish between red and green colors.     3    

Mammals like deer are the tiger’s main prey, and their dichromatic vision means they don’t see tigers as orange — they see them as green. That makes the tiger much harder to spot as it’s prowling behind a bush or crouching in the grass. Although green tigers would probably be even harder to spot, evolution (进化) just doesn’t work with the ingredients necessary to make green fur.     4     The only recognizably green mammal is a sloth, and its fur isn’t green in fact. That’s an alga that grows in its fur.

    5     There seems to be no evolutionary pressure, particularly for deer, which are the main prey of the tiger, to become trichromatic. That’s probably because the tiger doesn’t know it’s orange either. So, the evolutionary race really doesn’t exist for that color. It’s just that the tiger has evolved over the sweep of evolution to have a coloring, a hiding system, which protects it very well in its jungle setting.

Global warming is causing many physical risks such as droughts, wildfires, and floods.     1    (luck) , some countries have started planning ahead. The South Korean City of Busan, and other cities     2    (join) forces to build the world's first prototype(原型) floating city in order to get ahead     3     physical risks in recent years.

As the population rises, more and more people are being pushed to coastal cities.     4     , these regions are easily affected by floods and hurricanes. Part of climate change     5    (adapt) is building the kinds of cities that can withstand these risks. The technology and science     6    (use) in this first prototype city could be repeated in other cities.

The city of Busan,     7     is also bidding for World Expo 2030, is one of the most important maritime     8    (city) of the 21st century and an ideal location for the first prototype floating city.

The new floating city will consist of a series of hexagonal(六边形的) platforms and will benefit from a limestone coating that when     9    (expose) to an electric current, it can be used to repair itself. The city will be completely self-sufficient,     10    (develop) its own food and water, and will be immune to all kinds of climate change-related threats including category 5 hurricanes. All in all, the city will be a notable example of the cities of the future.

7 . Richard Turere walks through his family's farm just outside Nairobi National Park in Kenya. Goats, cows, and sheep eat grass peacefully on the farm while in the park nearby, lions wander leisurely, living in peaceful coexistence with the livestock. An extraordinary picture! How do livestock manage to live safely near these huge lions? It's all due to this young man's brilliant invention, Lion Lights.

Livestock is his family's entire livelihood—which is why whenever lions attacked their goats, sheep, or cattle, it was disastrous. There seemed to be no good solution to the problem until Richard began working on it. After a lion killed his family's only bull, Richard started experimenting with ways to scare off the lions. His first two attempts—fire and then a scarecrow—were unsuccessful. But one night in 2011, when he was walking around with a flashlight, he noticed that lions stayed away. That's when he realized: these big cats were afraid of moving lights!

Then Richard—who'd taken apart and studied machines since he was very small—began experimenting. Despite his lack of any formal training in electrical engineering, he fitted a system of flashing LED lights on poles around the farm. The flashing lights, which he made from vehicle indicator flashers, car batteries, and a solar panel, tricked the lions into thinking the grounds were guarded, keeping the lions away.

The word got out about the brilliant "lion-lights boy". Soon Richard was fixing the Lion Lights system for neighbors. Later, his invention won him a scholarship to Kenya's well-known Brookhouse International School. And when Richard was 13, he was invited to California to speak about his invention at a TED conference. These days, Richard still lives on his family's farm, and fixes the Lion Lights system for people all over Kenya, which functions efficiently. He dreams of becoming an airplane engineer and pilot, but he also works to arouse people's awareness about the need to support young Kenyan inventors like himself.

My friend has a sweater that her uncle bought in the 1970s. That sweater is still going strong and she wears it everywhere. Well-made, long-lasting clothing is    1     we should buy and wear. In reality, however,60% of clothing nowadays     2    (abandon)within a year of purchase, which produces vast quantities of waste that global landfills (垃圾填埋场) are struggling    3     (absorb).

If we choose long-lasting clothes, it helps solve two key    4     (issue) at once-overconsumption and the declining quality of many clothes in stores these days. A focus on quality would make us likely to pay     5    (much) for better-made items, which would reduce the desire to keep shopping, while slowing demand for fast fashion overall.

You could buy secondhand clothing, too, as    6     useful way to extend the lifespan (寿命) of items already    7     (create). But I've come to think that whether you buy something new or used       8     (matter) less if you commit to keeping clothes in use for decades. The same goes for    9    (nature) fibers; this xkw quality counts, of course,    10    it is less important if you throw away clothes within a few months from time of purchase. The most important thing is to make them last.

9 . Ever wondered if dogs can learn new words? Yes, say researchers as they have found that talented dogs may have the ability to grasp new words after hearing them only four times.

While previous evidence seems to show that most dogs do not learn words, unless eventually very well trained, a few individuals have shown some extraordinary abilities, according to a study published in the journal Scientific Reports.

“We wanted to know under which conditions the gifted dogs may learn novel words,” said researcher xuekw Claudia Fugazza from the Eötvös Loránd University in Hungary. For the study, the team involved two gifted dogs, Whisky and Vicky Nina. The team exposed the dogs to the new words in two different conditions.

In the exclusion-based task, presented with seven known toys and one new toy, the dogs were able to select the new toy when presented with a new name. Researchers say this proves that dogs can choose by exclusion when faced with a new word, they selected the only toy which did not have a known name.

However, this was not the way they would learn the name of the toy. In fact, when they were presented with one more equally new name to test their ability to recognize the toy by its name, the dogs got totally confused and failed.

The other condition, the social one, where the dogs played with their owners who pronounced the name of the toy while playing with the dog, proved to be the successful way to learn the name of the toy, even after hearing it only 4 times. “The rapid learning that we observed seems to equal children’s ability to learn many new words at a fast rate around the age of 18 months,” Fugazza says. “But we do not know whether the learning mechanisms(机制) behind this learning are the same for humans and dogs. ”

To test whether most dogs would learn words this way, 20 other dogs were tested in the same condition, but none of them showed any evidence of learning the toy names, confirming that the ability to learn words rapidly in the absence of formal training is very rare and is only present in a few gifted dogs.

10 . I saw my first tree today. Dad used to tell me stories about the trees that still existed when he was a boy. There weren’t very many even then, with the urbanization program in full swing.

The O’Brien home was one of the few examples of old-style wooden structures that hadn’t been destroyed in Boston’s urban-renewal campaign. The family had been able to avoid this because of its wealth and political influence, and the house was passed on through generations to the present. Old man O’Brien had no children, so when he died, the Urban Center bought it. Then an official discovered that the house had a backyard-in the yard was a live tree!

When the news of the tree’s discovery leaked out, quite a few sightseers stopped by to have a look at it, and the local government, realizing the money-making potential, began charging admission and advertising the place. By now it had become a favorite spot for family trips like ours.

Dad paid the fee and we walked through a doorway hidden in a bookshelf and into the backyard. I just couldn’t help noticing the tree!

It was located at one end of the yard, with a fence around it for protection. It was similar in form to the plastic trees I’d seen, but there was much more. You could see details more delicate than in any artificially made plant. And it was alive. But best of all was the smell-fresh, living smell, unfamiliar to the world outside with metal, plastic, and glass. I wanted to touch the bark, but the fence prevented me from doing so.

On the way back, I read through the brochures. One part said the O’Brien home would be torn down next year to make room for some insurance building, and the tree will have to go, too.

I just sat still, fingering the object in my pocket that I had picked in the O’Brien’s backyard. I think it’s called an acorn (橡子).