Most people know precious gemstones (宝石) by their appearances. An emerald flashes deep green, a ruby seems to hold a red fire inside, and a diamond shines like a star. It's more difficult to tell where the gem was mined, since a diamond from Australia or Arkansas may appear the same to one from the Democratic Republic of the Congo. However, recently, a team of scientists has found a way to identify a gemstone's origin.

    Beneath the surface of a gemstone, on the tiny level of atoms and molecules（分子）, lie clues (线索) to its origin. At this year's meeting of the Geological Society of America in Minneapolis, Catherine McManus reported on a technique that uses lasers (激光) to clarify these clues and identify a stone's homeland. McManus directs scientific research at Materialytics, in Killeen, Texas. The company is developing the technique. “With enough data, we could identify which country, which mining place, even the individual mine a gemstone comes from,” McManus told Science News.

    Some gemstones, including many diamonds, come from war-torn countries. Sales of those “blood minerals” may encourage violent civil wars where innocent people are injured or killed. In an effort to reduce the trade in blood minerals, the U.S. government passed law in July 2010 that requires companies that sell gemstones to determine the origins of their stones.

    To figure out where gemstones come from, McManus and her team focus a powerful laser on a small sample of the gemstone. The technique is called laser-induced breakdown spectroscopy. Just as heat can turn ice into water or water into steam, energy from the laser changes the state of matter of the stone. The laser changes a miniscule part of the gemstone into plasma, a gas state of matter in which tiny particles（微粒）called electrons separate from atoms.

    The plasma, which is superhot, produces a light pattern. (The science of analyzing this kind of light pattern is called spectroscopy.) Different elements produce different patterns, but McManus and her team say that gemstones from the same area produce similar patterns. Materialytics has already collected patterns from thousands of gemstones, including more than 200 from diamonds. They can compare the light pattern from an unknown gemstone to patterns they do know and look for a match. The light pattern acts like a signature, telling the researchers the origin of the gemstone.

    In a small test, the laser technique correctly identified the origins of 95 out of every 100 diamonds. For gemstones like emeralds and rubies, the technique proved successful for 98 out of every 100 stones. The scientists need to collect and analyze more samples, including those from war-torn countries, before the tool is ready for commercial use.

    Scientists like Barbara Dutrow, a mineralogist from Louisiana State University in Baton Rouge, find the technique exciting. “This is a basic new tool that could provide a better fingerprint of a material from a particular locality,” she told Science News.

    As a child, Alain Robert was afraid of heights. When he was 12, he returned home from school. At the front door of his building, he looked for his keys. he didn't have them. It was 3:30 and his parents worked until 6:00 pm. Alain looked at his apartment on the eighth floor. He saw an open window. He closed his eyes and imagined himself climbing the building. When he opened his eyes, he told himself ,"I can do it." Fifteen minutes later, he was in his house and his fear of heights was gone.

    Today, Alain still climbs buildings. In 2003 , he climbed a building in London dressed as Spiderman(蜘蛛人) to advertise the movie. In 2004, he climbed Taipei 101 (one of the tallest buildings in the world). To reach the top of a building, Alain uses only his hands and special shoes. He has no rope or other safety tools.

    Alain climbs as a hobby. He also does it to make money for charity. When he climbs, he wants to send a message to people. If you have a dream—something you really want to do—it can become real. But you must be brave and keep trying. If something bad happens, don't give up. Close your eyes and tell yourself, "I can do it."

    An interesting study posted on Facebook recently shows how men and women develop new interests as they mature(成熟).

    While women tend to take exercise seriously from the age of 34, men will wait until their 45th birthdays before working hard to get in shape.

    The average woman spends more time talking about sports, politics, career and money as she gets older.

    Women's interest in books reaches its peak(顶峰) at the age of 22, while that of men does so when they are in their 50s.

    Men start to change their focus from the workplace to other things after age 30, while women do not do so until eight years later. Both, however, care most about fashion at age 16.

    The research used anonymous(匿名的) data donated by thousands of Facebook users, recording the statuses, 'likes' and 'interests' they had posted on their profiles.

    It found the average woman talks about television most at 44, while men peak much younger, at age 31.

    Men are also most likely to see a film in a cinema at age 31, while women go out to see films most when they are only 19.

Men are most interested in travel at 29, women at 27, while women talk most about food and drink at 35, and men at 38.

    And if you are middle aged, a safe topic for anyone is the weather, which is a key interest for many as they reach 60.

    Stephen Wolfram, the British scientist who carried out the research, says, “It's almost shocking how much this tells us about the changes of people's typical interests.

    “People talk less about video games as they get older, and more about politics.”

    Qingming Festival, which falls on April 5 this year, is known as Tomb-Sweeping Day. The festival always appears about the beginning of April when spring has come. Not only is it a period for commemorating the dead, it is also a time for people to go out and enjoy nature.Where is the best place to go during the festival? Here are 3 popular tourist attractions.

    Jiuzhaigou Valley Scenic and Historic Interest Area

    In the spring, the sight of the Jiuzhaigou Valley is refreshing and touching. The ice and snow begin to melt, water and streams begin to flow and mountain flowers blossom. The air is filled with the fragrance of spring. The soft and lazy spring sun kisses the surface of the lake and new growth.

    Huanghuacheng Great Wall

    Huanghuacheng is the only lakeside part of the Great Wall in Beijing. It is one of the most popular destinations for a Great Wall hiking tour. It is a hit because of the "train for spring", namely a train that travels through fields full of cherry blossoms.It is extremely romantic to take this train in spring with someone you love.

    Mount Huangshan

    Of all the notable mountains in China, Mount Huangshan is probably the most famous and is found in the southern part of East China's Anhui province. It is known for its breathtaking natural scenery.In the spring, Mount Huangshan is fresh, tender and full of wild flowers, and the sound of birdsong also is pleasant in the quietness

    The pupils of Grangetown High have been busy getting to know their newest and tallest classmate — a 7-meter-tall giraffe outside their school.

    The giraffe is a huge sculpture (雕像). The school's headmaster noticed it in an artist's garden as he drove past one day, and thought it would be perfect for his school. “I knew everyone would love it," he said, "because our basketball team is known as the Grangetown Giraffes, and they wear giraffes on their shirts. So I asked them to write to the artist, asking how much it would cost to buy the giraffe. He was very kind and got it ready to deliver (递送) in six weeks — all for nothing! It was expected to arrive one Sunday morning, so that the pupils would see it when they got to school on Monday — at that time they had no idea that we were getting it."

    The artist, Tom Bennett was a university professor of chemistry before he retired in 2012 and only took up metalwork a couple of years ago. "I've always drawn pictures," he said. I can even remember doing it on my first day at school — I drew a horse. I wanted it to be the best horse picture ever, but I don't think I succeeded."Tom's first metalwork was a bicycle on which he and his wife could go cycling together, “It was the most uncomfortable bike ever created," he said, "so I gave up making bicycles and went into sculpture instead."

    Meanwhile the pupils at Grangetown High are very happy with their new classmate. "We're going to hold a competition to give it a proper name," said one girl. "Everyone likes the expression on its face, so perhaps that will give us some ideas."

    Let's look at the movies we can't wait to watch in 2019:

    Dumbo (March 29)

    Dumbo is a 1941 American film produced by Walt Disney Productions. The main character is an elephant who is nicknamed "Dumbo". Dumbo is always laughed at for his big ears, and he is rejected by the other elephants. With no parent to care for him, he is alone. But in fact, he is capable of flying by using his ears as wings. A live-action adaptation of the film directed by Tim Burton is scheduled to be released on March 29, 2019.

    Shazam! (April 5)

    Shazam! is an upcoming American superhero film based on the DC Comics character of the same name. Directed by David F. Sandberg, the film is set to star Asher Angel as Billy Batson, a teenage boy who can transform via the magic word "Shazam" into an adult superhero, played by Zachary Levi. It will be the first film version of the character since the 1941 series Adventures of Captain Marvel (the character's original name).

    Aladdin (May 24)

    Aladdin is a fictional character and the role of the film Aladdin (1992) based on Aladdin, a folk tale of Middle Eastern origin. He is voiced by Scott Weinger, while his singing voice is provided by Brad Kane. Aladdin never received a formal education, and has only learned by living on the streets of Agrabah. He has to steal food in the local market in order to survive. Mena Massoud is set to play a live-action version of the character in a live action adaptation of the 1992 film.

    Godzilla, King of the Monsters (May 31)

    Godzilla, King of the Monsters is a 1956 Japanese-American science fiction film, co-directed by Terry O. Morse and Ishiro Honda. It is a heavily re-edited American adaptation. For this new version of Godzilla, some of the original Japanese dialogue was translated into English, and some of the political, social and anti-nuclear themes were removed completely.