For many people around the world, a subway journey means speeding from one dull station to the next, surrounded by too many uncomfortable, impatient people. But on the Moscow Metro, taking the subway is like walking through a national heritage site. Depending on where you get off, you'll receive a brief course in architectural movements and face colorful glass windows, marble(大理石) columns, gilded(鎏金的) mosaics and painted scenes from Russian history.

    “These extraordinarily beautiful places are unlike any metro station I've ever seen, “says Vancouver-based photographer David Burdeny.

    When Burdeny, who himself has a master's degree in architecture, first found out about Moscow's metro stations, he was struck by the work of art. In all, he has photographed 20 of the most beautiful stations.

    Burdeny had originally planned to focus on Russian stations more generally, taking photos of examples in both St. Petersburg and Moscow.

    “But when I saw the stations in Moscow, they just completely blew away the St. Petersburg ones,” he says.

    Shooting in the subway sounds simple, but it is not without challenges. For one thing, Burdeny had to figure out a way to access them between 00:30 a.m. and 5:30 a.m., when the stations were closed.

    In the end, he settled on Arbatskaya Metro Station, whose vaulted(拱状的) arches he found the most beautiful. But it also represented a challenge he was not sure if he was able to overcome: conveying the hugeness of the spaces. The Arbatskaya platform, for example, stretches 820 feet.

    “Some of the arches are quite long,” he says. “When you enter them, they're just so completely grand.”

    Traveling without a map in different countries, I find out about different ways of directions every time I ask “How can I get to the post office?”

    Foreign tourists are often puzzled in Japan because most streets there don't have name signs. In Japan, people use landmarks (地标) in their directions instead of street names. For example, the Japanese will say to travelers, “Go straight down to the corner. Turn left at the big hotel and go past a fruit market. The post office is across from the bus stop.”

    People in Los Angeles, the US, have no idea of distance on the map: they measure distance by time, not miles. “How far away is the post office?” you ask. “Oh,” they answer, “it's about five minutes from here.” You don't understand completely, “Yes, but how many miles away is it, please?” To this question you won't get an answer, because most probably they don't know it themselves.

    People in Greece sometimes do not even try to give directions because tourists seldom understand the Greek language. Instead, a Greek will often say, “Follow me.” Then he'll lead you through the streets of the city to the post office.

    Sometimes a person doesn't know the answer to your question. What happens in the situation? A New Yorker might say, “Sorry, I have no idea.” But in Yucatan, Mexico, no one answers “I don't know.” People there believe that “I don't” is impolite. They usually give an answer, but often a wrong one. So a tourist can get lost very easily in Yucatan! However, one thing will help you everywhere in the world. It's body language.

    Dr. Sasaki knew the first-night effect probably has something to do with how humans evolved.

    The puzzle was what benefit would be gained from it when performance might be affected the following day. She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators (捕食者). This led her to wonder if people might be doing the same thing. To take a closer look, her team studied 35 healthy people as they slept in the unfamiliar environment of the university's Department of Psychological Sciences. The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains. Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second, taking more than twice as long to fall asleep and sleeping less overall. During deep sleep, the participants' brains behaved in a similar manner seen in birds and dolphins. On the first night only, the left hemispheres (半球) of their brains did not sleep nearly as deeply as their right hemispheres did.

    Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps (蜂鸣声) of the same tone and irregular beeps of a different tone during the night. She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

    The arm bones of women who lived 7-000 years ago show a surprising level of strength-even higher than today's professional athletes. That's according to a first-ever study comparing prehistoric(史前的)bones to those of living people. The finding suggests a revision of history — the everyday lives of prehistoric women were filled with hard labor, rather than just sitting at home doing lighter tasks while the men struggled and fought for life.

    “Before the study, there are no clear records describing how our ancient ancestors lived. It can be easy to forget that bone is a living tissue, one that responds to the difficulties we put our bodies through,” said lead author Alison Macintosh. “Physical force and muscle activity both put pressure on the bone. The bone reacts by changing in shape, thickness and other aspects over time. ”

    Previous studies only compared female bones to contemporary male bones, the researchers said — and that's a problem, because the response of male bones to stress and change is much bigger than that of women. For instance, as humans moved from a hunter-gatherer lifestyle constantly on the move to a more settled agrarian (农耕的)one, changes can be observed in the structure of the shinbone (胫骨) — and these changes were much more evident in men.

    However, a comparison of the bones of prehistoric women to the bonos of living female athletes can help us work out a more accurate picture of what those prehistoric women were doing. “By analyzing the bones of living people and comparing them to the ancient hones, we can start to explain the kinds of labor our ancestors were performing,” Macintosh said. What they found was that women's leg strength hasn't changed a great deal, but their arms used to be very powerful. Prehistoric women, the researchers found, had arm strength 11〜16 percent stronger than those of modern rowers, and 30 percent stronger than those of non-athletes.

    Winter sports tend to be more dangerous than summer sports — they take place mostly outside at the mercy of ice or snow, involving (牵涉) metal edges, extreme speeds and crashes. Skeleton (俯视冰梭), however, stands apart as one of the most difficult and least accessible of all the winter sports. Adam Edelman, Israel's first Olympic skeleton athlete, would like to change that.

    Edelman was the 10th athlete named to the 2018 Israeli Olympic Team. Qualifying for the Olympics in any sport is impressive. But it's more impressive if you qualify for the Olympics after only four years in the sport — and without a coach.

    Edelman was first introduced to skeleton watching the game on television in late 2013. Sports have always been a part of his life. He grew up playing football and was a goalkeeper on the Massachusetts Institute of Technology football team. Ready for a new challenge, he set his sights on the Olympics.

Without a coach, Edelman learned to drive by watching endless hours of YouTube videos and taking more runs than anybody else on the track. “When everybody else would take three runs per day, I would take six to eight.” he recalled.

    Succeeding in skeleton takes a large amount of athletic ability and technical skill, but there's one more element (因素) required, one that can't be taught. “These tracks but built in the middle of nowhere, and it's gray and cold. You haven't seen your family in seven months and you really just want to give up. To continue, it takes tenacity.” Edelman said.

    Edelman is already looking beyond Pyeongchang. The 2022 Olympics could be in his future, but whether he continues to compete or not, he promises to stay in Israeli sports as long as possible-as instructor or as a coach.

Artificial intelligence（Al）has the potential to develop more efficient methods of farming in order to fight global warming. 

 Global warming threatens every aspect of our everyday lives, including crop production. It will reduce the soil moisture（水分）in areas close to the equator according to a study. We are already seeing the negative impact of these changed growing conditions on our crop production. Climate change harms poorer countries that do not have the money to import food. The result is growing food insecurity. However, agriculture is not just affected by global warming—agriculture is part of a vicious（恶性的）cycle in which farming leads to global warming, which in turn destroys agricultural production. The process of clearing land for agriculture results in widespread deforestation（毁林）and contributes to 40 percent of global methane production. Therefore, to deal with climate change, it is necessary to ensure reforestation—but how? What is the path to efficient, environmentally-conscious farming?

This is where AI enters the scene. Farmers use AI for methods such as precision agriculture; they can monitor crop moisture, soil composition, and temperature in growing areas, enabling farmers to increase production by learning how to take care of their crops and determine the ideal amount of water to use. Furthermore, this technology may help reduce deforestation by allowing humans to grow food in urban areas. It could be especially beneficial for countries in Latin America and the Caribbean, where much of the population lives in cities. 

However, AI is far from a silver bullet—it could actually contribute to global warming as well. Due to the large amount of data that AI needs to process, training a single AI releases five times the emissions that an average car would give off during its lifetime. Further, securing access to AI on a global scale may pose some challenges. Countries will need experts in the field who can successfully use the technology and Internet connection, neither of which are always readily available. Therefore, there is still a long way for developing countries to take advantage of the benefits of AI. 

Given these concerns, global leaders must consider the potential costs, and the environmental consequences of data processing before developing AI for use in agriculture.