Even if trees cannot walk, they are still on the move.

    In parts of the Arctic, entire forests are moving northward. Across the Arctic, temperatures are rising faster than anywhere else in the world. As that happens, the tree line that marks where forests stop and the treeless tundra(冻土地带) starts has been shifting northward. Trees growing along the tree line must protect themselves from the cold wind. To do this, plants tend to grow horizontal(水平的) branches low to the ground. The energy it takes for trees to grow this way means they don't have enough energy to make seeds.

    But as Earth's climate has been warming, trees no longer have to just grow horizontally. Many can instead grow up toward the sky. This takes less energy. And with all the leftover energy. these trees have started producing more seeds. This happens especially in places where the white spruce(白云杉) grows.

    White spruce, which is a North American tree, is quite able to produce a lot of seeds, which can move long distances in the wind. When wind-blown seeds end up on the tundra beyond the tree line, they eventually can sprout(发芽) new trees. This explains how a forest can move. Of course, the process would work only if the tundra were warm enough. But in recent years, the whole planet has been warming.

    New trees will provide shelters for some snow, keeping the sun's rays from making the white surface disappear. Instead, the trees absorb the sun's heat. This warms the surrounding air. The extra warmth encourages even more trees to produce seeds. That further boosts a forest's ability to expand. In addition, more trees will trap more snow, preventing much of it from being blown away. Snow can trap heat in the soil below, which encourages trees to grow. The recent rise of temperature has helped more trees grow. The recent rise of temperatures has helped more trees grow past the tree line. People worry about impacts on the animals that depend on frozen conditions for food and shelter.

    If you want to travel from Xi'an to Chengdu by train, it will take about 16 hours. But starting this month, the new Xi'an-Chengdu high-speed railway will shorten this travel time to three hours.

    The 643-kilometer line is China's first high-speed railway to run through the Qinling Mountains, which form a natural boundary (分界线) between China's north and south. With a speed of 250 km per hour, it's also the first mountain-heavy train line to provide a 4G network. Along the way, the train passes through two areas for rare (稀有) wild animals — one for pandas and the other for crested ibises (朱鹮).

    To reduce the railway's influence on the animals, workers and experts have designed and built the railway to be environmentally friendly. There were 345 wild pandas living in the Qinling Mountains. China currently has 1,864 wild pandas in total, according to the Xinhua News Agency.

    To avoid disturbing the pandas, the railway was designed to run through tunnels (隧道) within the area. Protective shields (防护屏) are placed near the entrance of each tunnel to stop animals from going in.

    To protect the thousands of crested ibises that fly near one part of the railway, protective nets have been set up to make sure the birds will not fly into a train.

    The nets are about 32 km long and 4 meters high. Experts tested different shapes and materials for building the nets before making their final choice.

    JERUSALEM—Israel's Environmental Protection Ministry asked citizens Wednesday to avoid unnecessary physical activity and stay indoors, as a serious sandstorm struck the Middle East in a thick yellow haze (霾) for a second day with no hope to see things clearly.

    The ministry said heavy levels of dust and sand in the air were a threat to cities throughout the country. The ministry's website advised pregnant women, the elderly and those with heart and respiratory (呼吸的) conditions to stay indoors, and asked schools to keep children indoors.

    The emergency service Magen David Adom reported that it has treated more than 300 Israelis suffering from breathing problems, and that hospitals have more respiratory-related patients, including a large number of the elderly and those with asthma and related conditions.

    The domestic Israeli airlines Arkia and Israir continued to ground their flights to Eilat because of reduced visibility.

    The sandstorm has affected Egypt, Jordan, Iraq, Lebanon and Syria, where at least five deaths have been reported.

    "There has been nothing that came close to the magnitude of this sandstorm," said Daniel Rosenfeld, a professor with the Institute of Earth Sciences at the Hebrew University in Jerusalem.

    "While Israel has experienced a number of sandstorms in the past, they started from the Sinai Desert and the Sahara Desert to the south and were joined by winter windstorms that cleared the air," he said. In this case, the storm comes from Syria and Iraq to the north and east.

    Because the storm is hitting during the summer, at a time of both little wind and severe heat and humidity, forecasters expect the particles to remain in the air throughout the weekend and possibly into next week.

    "This is really puzzling," said Rosenfeld, adding that he and his colleague will conduct research into the origins of the unprecedented (前所未有的) storm. (326 words)

    Your colleague's sharp comment keeps replaying in your mind. Two of your students are trapped in a "he said/she said" battle. When you reflect on your emotional reactions, you sometimes get caught up in cycles of negative feelings, which can make you feel even worse. If so, the answer may lie in a skill called "self-distancing", the ability to take a step back and view yourself more objectively. According to a research, when people adopt self-distancing while discussing a difficult event, they make better sense of their reactions, experience less emotional suffering, and display fewer signs of stress.

    But what might self-distancing look like in action? Consider a typical "he said/she said" student conflict where they are each focusing on their own feelings. One is thinking, "I can't believe he did that to me." And another insists, "She really hurt my feelings." However, if you ask them to take the self-distancing, they might step outside of themselves and ask broader questions: "Why was he so hurt in this situation?" or "How did her anger affect him?"

    Although this approach may sound too simple to be effective, studies indicate that a change in point of view can have a powerful effect on the way people think, feel, and behave. Here are several different techniques you can try.

    First, consider how a thoughtful friend might respond after quietly observing their situation. Besides, avoid using the pronoun "I". Focus on using third-person pronouns, he, she, they, and they were able to see the stressful event as challenging rather than threatening. Finally, ask yourself, "How would I feel about this one week from now or ten years from now?" This form of mental time travel may be effective because our attention is directed away from our immediate, concrete circumstances.

    There's a world of difference between a horror movie and a comedy—the former scares you half to death while the latter leaves you rolling on the floor with laughter. But try watching them without the background music and you just might decide they're not so different after all. Music and movies have been closely connected since the beginning of the film industry—even before the voices of actors were recorded. In movies, music helps to provide a sense of time and place, convey ideas about the characters and, most importantly, draw emotions out of the audience.

    Studies have long shown that our heart rates and anxiety levels rise and fall depending on the speed of the music we hear. Using this knowledge, composers use sudden changes in film music speed to create fear among audiences. Slowing the speed of the music will have the opposite effect, bringing about a sense of peace or a dreamlike quality. The use of dissonant (不和谐的) tones and noises is another technique that heightens tension. Humans naturally become unnerved when we hear dissonant sounds because such noises are usually associated with danger, like those that animals make to warn against predators (捕食者).

    As crucial as it is, the best film music is subtle. All that audiences are supposed to feel is a heightened sense of emotion—they shouldn't realize what's causing it. Only when the music is taken out of the film should audiences understand its effects.

    In keeping with this principle, some filmmakers are even using what's called "infrasound" (次声波) to arouse fear. While we may not be able to hear it because its frequency is below the range of the human ear, infrasound has been proven to cause anxiety, tremble and even sorrow. For example, infrasound was used in the soundtrack of the 2007 horror movie Paranormal Activity, and audiences reposed extremely high fear levels despite the 1ack of action throughout the movie. "It doesn't affect everyone equally," said British science writer Philip Ball, author of The Music Instinct, but he predicted that "we will see more of it used in movies in the future".

    Like many other people who speak more than one language, I often have the sense that I'm a slightly different person in each of my languages­more confident in English, more relaxed in French, more emotional in Czech. Is it possible that, along with these differences, my moral compass (指南针) also points in somewhat different directions depending on the language I'm using at the time?

    Psychologists who study moral judgments have become very interested in this question. The findings of several recent studies suggest that when people are faced with moral dilemmas (困境), they do indeed respond differently when considering them in a foreign language than when using their native tongue.

    In a 2014 paper led by Albert Costa  volunteers were presented with a moral dilemma known as the "trolley problem": imagine that a runaway trolley is moving quickly toward a group of five people standing on the tracks, unable to move. You are next to a switch that can move the trolley to a different set of tracks, therefore sparing the five people, but resulting in the death of one who is standing on the side tracks. Do you pull the switch?

    Most people agree that they would. But what if the only way to stop the trolley is by pushing a large stranger off a footbridge into its path? People tend to be very hesitant to say they would do this, even though in both situations, one person is sacrificed to save five. But Costa and his colleagues found that presenting the dilemma in a language that volunteers had learned as a foreign tongue dramatically increased their stated willingness to push the sacrificial person off the footbridge, from fewer than 20% of respondents working in their native language to about 50% of those using the foreign one.

    Why does it matter whether we judge morality in our native language or a foreign one? According to one explanation, such judgments involve two separate and competing ways of thinking­one of these, a quick, natural "feeling," and the other, careful deliberation about the greatest good for the greatest number. When we use a foreign language, we unconsciously sink into the more careful way simply because the effort of operating in our non-native language signals our cognitive (认知的) system to prepare for difficult activity.

    An alternative explanation is that differences arise between native and foreign tongues because our childhood languages are filled with greater emotions than are those learned in more academic settings. As a result, moral judgments made in a foreign language are less filled with the emotional reactions that surface when we use a language learned in childhood.

    There's strong evidence that memory connects a language with the experiences and interactions through which that language was learned. For example, people who are bilingual (双语的) are more likely to recall an experience if reminded in the language in which that event occurred. Our childhood languages, learned in the middle of passionate emotion, become filled with deep feeling. By comparison, languages acquired late in life, especially if they are learned through limited interactions in the classroom or dully delivered over computer screens and headphones, enter our minds lacking the emotionality that is present for their native speakers.