Sometimes, you just can't help it. Maybe you're watching a sad movie, or thinking about the friend who moved away. Next thing you know, your eyes are watering, and you havetears running down your cheeks. Why do peoplecry when they are emotional? What are tears? Scientists are working hard to find the answers to these questions.

    Ad Vingerhoets is a professor of psychology at Tilburg University, in the Netherlands. He is one ofthe few scientists in the world who have studied crying. According to Vingerhoets, there are three types of tears. Basal tearsare the first type. Theylubricate(润滑) the eyes andact as a protective barrier between the eye and the rest of the World. Next arereflex tears. They wash youreyes clean when something gets in them. Finally, there are emotional tears. “These are released in response to emotional states, ”explains Vingerhoets. “Especially when we feel helpless.”

    Scientists believe that crying has something to do with how humans developed and learned to depend on each other.“Humans are very complex social creatures,”says Lauren Bylsma, a professor at the University of Pittsburgh, in Pennsylvania.“It seems that tears serve to arouse help and support from others," She says. “Another reason we weep is that humans have the longest developmental period of almost any animal. It takes along time to grow up. ”

    Vingerhoets agrees. “I think that the reason why humans shed tears(流眼泪) has somethingto do with our childhood,”he says. “That's the time when we are stir dependent on adults for love and protection and care. The major advantage of emotional tears is that you can target them at a specific person.”Vingerhoets says this ability to target someone could have come in hand in prehistorictimes, when humans were living among dangerous animals. Crying couldattract predators(捕食者). Tears were asafer way to get attention. In this case, it is better to use a silent signal to ask for help,”he says.

    Vingerhoets and Bylsma do frequent studies to better understand why humans cry. According to Byhma, there is still much more to discover. “It's surprising,”she says,“how much we still don't know.”

    What would you say if we told you that you could learn to speak a new language in only 7 days? Pretty unbelievable right? But how could it be? To find out,we spoke to David-one of our brave Babbel learners—to see how the Babbel app successfully got him speaking Norwegian(挪威语)in just one week.

How much time did you learn each day?

    I didn't need to give my entire life over to learning Norwegian. Each Babbel lesson takes only 15 minutes, and I set myself the achievable aim of finishing three Babbel lessons daily.This took only 45minutes each day.

How did the Babbel app help you learn so quickly?

    The Babbel app has a course plan for beginners that taught me how to make sentences in Norwegian within the first few days. Then I was able to personalize my learning by selecting single-topic lessons on eating, drinking, music, culture, traveling and so on. This allowed me to quickly enlarge my vocabulary!

    This way of learning kept me highly active,and made sure I wasn't bored to tears with grammar practice that we all remember from school!

    “After 7 days I was able to introduce myself in Norwegian,talk about my hobbies and interests, and most importantly,communicating with a native Norwegian speaker in a real conversation and I could even play a joke or two!”

    Would you introduce this app to others?

    Certainly! Babbel has 14 languages to choose from so if you're thinking about brushing up on your German for a business trip, or learning a bit of Portuguese (葡萄牙语) for next year's summer vacation, you'll be happy to hear that you only need an app, 7 days of learning to get you conversational.

    How to fight California's wildfires? It's an “all of the above” respond.

There might, indeed, be a need to make it easier to thin dying or dead trees out of thickly forested areas, reducing the fuel for wildfires. But the problem is actually more complicated. Even if dead trees are removed, the dry bushes act like kindling (引火物) when wildfires spread.

    Even more to the point, thick forests were not a factor in these recent California's fires. “They're using these fires to talk about forest management that has nothing to do with the landscape in which the fires are occurring,” says Chur Miller. W. M. Keck Professor of Environmental Analysis and History at Pomona College in Claremont, California.

    Climate change is making wildfires worse. The resulting unpredictable weather patterns have created shorter, wetter winters in California, producing a sudden, heavy growth of brushes, grasses and trees. After winter, the state's ongoing drought and record- high summer temperatures draw water out of the plants, making them near-perfect kindling. With the hot and dry Santa Ana winds of fall, fires explode out of control.

    Yet these tragedies can't be blame only on global warming. Wildfires are actually a vital of the state's ecosystem. Lodgepole pines (松树), for example, grow well in fire-prone areas where millions of structures have been built in rural areas of California since the 1940s.When they bum, the cost in lives and treasures skyrockets.

Answering these disasters with a one-dimensional solution helps no one, although it might score short-term political points. The proper response includes placing limits on residential expansion into wildlands; better management and removal of dry brushes and continuously addressing the growing concern of climate changes.

    In other words, the solution isn't either/or. It's all of the above.

    People can't see you when you're speaking on the phone, but they can hear you. So, the way you speak is especially important. In fact, researchers have calculated that 80% of communication over the phone is through your tone of voice; and only 20% is from the words you use. Here are our top tips on how to speak over the phone.

    ①Facial Expressions

    Your facial expression can influence your voice. For example, if you smile, your voice will sound warm and friendly, just the opposite, if you have an angry look on your face, it can make you sound unpleasant.

    ②Volume

    If you speak too loudly, you could sound angry. And if you speak too softly, it'll be difficult to hear you. So, speak loudly enough to be heard clearly, but not so loud that you're shouting.

    ③Pace

    The pace of your voice is how quickly you speak. And this can show how you feel. For example, an angry person might speak faster than normal. Or a downhearted person might speak very slowly. Try speaking a little more slowly than normal. This will make you sound confident, and it'll make it easier for the other person to understand you.

    ④Gestures

    Gesturing can influence the tone of your voice. When you gesture, you bring more air into the lungs, which can make your voice sound warmer. Gestures are also useful to help you stress the right words or even find the words you need. The best thing about gesturing during a phone call is that no one can see what you're doing, so you can gesture as wildly as you like!

    ⑤Movement

    If you're feeling nervous, stand up and move around. It will reduce the nervousness in your body and help your voice to sound more confident.

    ⑥Pauses (停顿)

    Using pauses every now and then can help you to slow down. This will make you sound more confident and in control. Also, if you pause after giving some new information, it'll give the other person time to understand it. At the same time, listen to how the other person uses pauses. They could tell you something about the speaker's feeling. For example, when a speaker is really angry, he might use pauses and says, "I…am…so…angry…"

    My family lives in Texas. I was born and brought up in Texas and I am a graduate of the University of Texas. However, around my second year in law school, I wanted to make a great change, which was almost unheard of for Texans: I wanted to leave!

    I realized this after completing my first year­year internship(实习期) I knew I wanted something different and my chance came during the 2011 Super Bowl in Dallas. A snowstorm blanketed the entire city in snow and thousands of people were gathered. I overheard that StubHub, a big company from a great city, San Francisco, was throwing a party next door to my hotel. I thought if l could get an internship, I could leave for the summer and at least see what it was like. Yes, it was a huge leap. I told myself I was ready.

    There was just one problem: I wasn't invited to the StubHub party. But you know I'm the type of person who goes for something she wants. Needless to say, I crashed the party and found my way to the president. I kindly introduced myself and then asked if they had a legal internship program. Guess what? They accepted my request to be a legal intern, even though no such program existed.

    Although the legal department didn't have a permanent position for me, the experience has shaped my life. Working for a great company in San Francisco, I'm incredibly happy for making my decision to leave Texas.

    By leaving Texas, I learned that it is so much more rewarding to try the unfamiliar than to stay in the comfortable. Exploring the unfamiliar is how you'll understand what fits your life. I say, dive in head first.

    Are you interested in travelling? Here are famous national parks where travellers mostly like to go in America.

    ⒈Great Smoky Mountains National Park

    Visitors: 11,388,893

    The name "Great Smoky Mountains" comes from the fog over this mountain range situated along the North Carolina-Tennessee border. Established in 1934, it is not just home to a diverse ecosystem of plants and animals, but also home to rich Appalachian cultures. Visitors there can see over 100 waterfalls, go boating on Fontana Lake and hike the Appalachian Trail. It's also an excellent vantage point to see the leaves change in the fall.

    ⒉Grand Canyon National Park

    Visitors: 6,254,238

    The Grand Canyon is the result of over 70 million years of geological events creating the Colorado Plateau, glaciers and valleys, while the Colorado River carved its way through the valleys. It is truly a natural splendor!

    When President Roosevelt first visited it in 1903, he said, "The Grand Canyon fills me with awe. It is beyond comparison – beyond description."16 years later, it was signed by President Woodrow Wilson, officially viewing the Grand Canyon a national park.

    ⒊Yosemite National Park

    Visitors: 4,336,890

    In addition to being a national park, Yosemite is designated as a World Heritage Site. Yosemite National Park is in Central California in the western Sierra Nevada. Though it covers around 1,168 square miles of area, visitors spend most of their time in the 5.9 square-mile area of the Yosemite Valley where there are some most famous sites like Yosemite Falls, and Cook's Meadow Loop.

    ⒋Zion National Park

    Visitors: 4,504,812

    Settled in Southwestern Utah is Zion National Park. It has some of the most unique landscapes packed with mountains, valleys, rivers, desert and forests.

    Zion National Park is also an important place to study ancient humans who made the area their home about 8,000 years ago. Some of the park's most notable attractions include Angel's Landing, Kolob Arch, the Narrows, etc.