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.

    Sitting on the sofa in her family's Michigan home in 2009, looking through the Guinness World Records, 10 year-old Winter Vinecki was surprised to find that the record for the youngest person to complete a marathon on every continent was held by a 27-year-old man. “I can beat that,” she declared. “For Dad. ” And she had every reason to believe she could.

    A natural athlete since the age of 5, Winter had been running together with her mom and uncle, both athletes, and competing in races across the country. Soon, her name was appearing in national competitions. Trophies (奖牌) lined her walls.

    But in 2008, at the age of 9, Winter stopped racing for medals. In May of that year, her father found out he had caught a rare cancer. To raise awareness and funds to fight the disease. Winter started an organization called I earn Winter. Just 10 months after his diagnosis, her father passed away.

    Over the next three years, Winter came first in 20 of the 37 races in which she competed, including four Junior Olympics Cross Country Championships. Along the way, she raised over $ 400,000 to help find a cure for cancer.

    Now 14, Winter is working on her world record to win her cause a place in the Guinness World Records. She recently completed her first marathon in Eugene, Oregon, a race normally limited to runners over 16, finishing in an amazing 3:45:04. “I'm used to racing with adults, and I think it's kind of fun to race past them,” said Winter before the race.

    With six continents to go, Winter has just begun a journey that will take her two years. “Every time I step to a starting line,” Winter says, “I have one thought in mind: keeping my dad's spirit alive.”

    You are going to read three competitions which offer holidays as prizes.

    Competition One

    Competition Two

    Competition Three

    Most foodies (吃货) agree that eating healthy food is important. But sometimes making good food choices can be tough. Now, there are apps that can help people learn about the food they eat to improve their diets and their dining out experiences.

Cheese & Wine Pairing app

    Wine and cheese can be a great combination. But which wines go best with which cheeses? Max McCalman's Cheese & Wine Pairing app can help. It provides information about hundreds of different cheeses and advises wines to pair with each. Max McCalman's Cheese & Wine Pairing app is free for iPhones and iPads.

Calorific app

    What does 200 calories look like? It can be hard to picture. Calorific provides images of 200 calories worth of food. The pictures can help people on a diet and those who just want to eat healthier food. The app is free for iPads and iPhones. There is also a version that provides more information for a price.

    HappyCow app

    Vegetarians do not eat animal meat. Vegans do not eat any animal products. The HappyCow app is made for both groups. Users can search for vegetarian-vegan restaurants and stores around the world. A free version of HappyCow is available for Android that has ads and requires an Internet connection.

    LocalEats app

    Restaurant chains, like McDonald's, can be found almost anywhere a person might travel. But sometimes travelers want to eat like locals. LocalEats is designed for that. It lists locally owned restaurants so users can try foods from that area. The app costs about a dollar.

    Pangolins (穿山甲) are strange-looking creatures, covered with hard scales (鳞). They can roll up into a ball to protect themselves from enemies and have tongues that are longer than their bodies.

    Pangolins have recently become the focus of Chinese people. A screenshot (截屏) of a micro blog post showing some people eating pangolins at a feast spread. A few days later, people were angered again by pictures showing people eating protected animals, including pangolins.

    Yet this is only the tip of the iceberg. Many more pangolins have been hunted or killed. According to the International Union for Conservation of Nature (IUCN), more than 1 million of them have been killed or sold in the last 10 years. It also said that they are the most illegally traded mammals in the world. In September 2016, the IUCN added the pangolin to the world's "endangered animals list". They are now more endangered than pandas.

    A growing trade of their scales and meat is the main reason for their decline in numbers. Many people in Asia and Africa consider pangolin meat is delicious. Some people even think pangolin scales have medical qualities. However, their scales are made of keratin (角蛋白), the same material human fingernails are made of.

    Luckily, the situation is getting better. World Pangolin Day is on the third Saturday of February each year. It's a day to help people know more about pangolins. The government now stops anyone from buying and eating pangolins in China. Breaking this law is regarded as a crime. The trade of pangolins across the world is also not allowed, according to the Convention on Trade in Endangered Species of Wild Fauna and Flora.

    Dr Dian Fossey, one of the world's leading women scientists, had a remarkable career. The work she devoted her life to protecting and studying the mountain gorillas (大猩猩) of Africa—has proved highly effective and has resulted in the steady (平稳的) increase of this most endangered great apes.

    Fossey made her first trip to Africa in 1963. Three years later, she returned to Africa to begin a long term study of the mountain gorillas. She set up camp in the Democratic Republic of Congo but moved to Rwanda because of political reasons in 1967. She established her "Karisoke" Research Centre camp on September 24, 1967.

    Fossey's aims were to study gorilla ecology (生态学) and social organization. She found that in order to achieve this, she needed to recognize individual gorillas, which required that the gorillas get used to her presence (出现). By copying gorillas' behaviour and sounds, Fossey began to gain their trust, and in 1970 an adult male gorilla she had named "Peanuts" reached out to touch her hand.

    Close observations over thousands of hours enabled Fossey to gain the gorillas' trust and bring forth new knowledge about their behaviour. Stories and photographs of her work were published in National Geographic Magazine and elsewhere.

    In 1977, one of Fossey's favorite gorillas, Digit, was killed by poachers and she established the Digit Fund to help raise money for gorilla protection efforts in the same year.

    On December 26, 1985, Fossey was murdered while going back to her house in Karisoke. Her body was discovered near the research centre. Most probably? Dian Fossey had been killed by the poachers she'd fought against. On her tombstone (墓碑): "No one loved gorillas more..."

    In 1988, the life and the work of Fossey were made into a movie based on her book.