The streams are about 12 to 15 feet wide and 300 feet or more long, scientists said. "What we're dealing with is wet soil, thin layers of wet soil, not standing water," said Aifred  McEwen of the University of Arizona at Tueson! the principal scientist for the Mars Reconnaissance Orbiter's high-resolution imaging experiment,

     Because liquid water is essential to life, the findings could have major implications for the possibility of Martianlife, There searchers said further exploration is needed to determine whether microscopic life exists on the planet.

    The presence of liquid water could also make life easier for astronauts visiting or living on Mars. Watercould be used for drinking and for creating oxygen and rocket fuel. NASA's goal is to send humans there inthe 2030s.

    The evidence of flowing water consistslargely of dark, narrow streaks(条痕) on the surface that tend to appear and growd uring the warmest Martian months and fade the rest of the year.

    Mars is extremely cold even in summer,and the streaks are in places where the temperature is as low as minus 10 degrees Fahrenheit. But salt can lower the freezing point of water and melt ice.

    The source of the water is a mystery. Scientists noted it could be melting ice. It could be an underground a quifer, which is rock or sand that can hold water. It is possibly water vapor from the thin Martian atmosphere, Or it may be a combination Michael Meyer, lead scientistfor NASA's Mars exploration program, said the only definitive way for now to determine whether there's life on Mars is to collect rocks and soil foranalysis on Earth - something a U.S. lander set for lift-off in 2020 will do.

    Does the future of filmmaking lie in virtual reality (VR) films?

    An ambitious team led by Yale senior Celine Tien might hold the answer to that question.

    Tien produced,directed and acted in Pippa's Pan,which she says is “one of the world's first live-action VR films.”The film,which was completed in April,mixes live action with VR sections.Some of the characters were created via animation（动画）and other techniques that distinguish the film from 360° VR videos like the ones frequently seen on YouTube.

    “360° VR videos are stagnant,which means you don't move with them and see a 360° view of whatever they're filming.”Tien explained.“What we're doing is immersive（沉浸式的）VR.When you put on the goggles (a kind of special glasses) you can physic.ally walk around in the space,pick up objects and engage with the environment.It's a huge difference.”

    The immersive VR film experience is different for everyone who interacts with the medium,but that doesn't mean the film's ending will change for each viewer.

    The film stars two Chinese-speaking actors."It's a love story about a woman suffering from Alzheimer's disease who is trying to bring back memories of her husband,"Tien said.

    The film has already been recognized by the VR industry.After handing in a short demo to the AT&T Developer Summit Conference,Tien and her team were invited to Las Vegas in January,where they came in third place.

    If you're dying to see the film already,your choices area bit limited: Pippa's Pan can't be seen in movie theaters unless they happen to have VR goggles available.According to Tien,many theaters in China will soon have the ability,which makes sense considering China is the film's target market.

    Pippa's Pan will be released in three languages: Chinese,English and Korean.“It can get spread in different ways: at film festivals with VR set ups and through HTC or Oculus headset stores,”Tien says.“If you have VR goggles you can download it and experience it yourself.We will also cooperate with movie theaters that have VR set ups.”

    For over 70 years, UNICEF has been putting children first, working to protect their rights and provide the assistance and services they need to survive and develop all over the world.

    It's the end-of-year giving season, and UNICEF has lots of good news to share about the influence its supporters have had on the lives of children. Thanks to its generous donors, UNICEF has helped save more lives than any other humanitarian organization.

    Monthly donors are a major reason why UNICEF can make that claim, according to Karla Coello, UNICEF USA Senior Director for Monthly Giving. “Last year, UNICEF responded to 377 humanitarian emergencies, from conflicts to natural disasters,” says Coello. “Emergency appeals bring in important revenue - but after the emergency, there are still a lot of things children need to make life bearable. That's what our monthly donors provide.”

    When drought destroys crops, conflict forces families from their homes, an epidemic breaks out or a disaster strikes, children suffer most. And in some countries, even the best of times are dangerous for its youngest citizens. Every day more than 15,000 children under 5 die from preventable causes.

    Protecting children before, during and after a crisis requires a reliable source of funding. The constant stream of revenue provided by monthly donations enables UNICEF to reach children with what they need most when they need it, prepositioning emergency supplies before a disaster strikes and continuing to build sustainable solutions after an immediate crisis has subsided.

    Monthly giving is also important to funding large-scale interventions(介入). Thanks to UNICEF's global immune campaigns, the world is now nearly free of polio(小儿麻痹症)and there are only 14 countries where mothers and children still face maternal and neonatal tetanus(破伤风)deadly threat. And UNICEF programs in 120 countries are helping to prevent and treat malnutrition, which is linked to nearly half of all deaths of children under 5.

    “UNICEF USA monthly donors are our most engaged, most dedicated supporters,” says Rebecca Volpe, UNICEF USA Manager, Monthly Giving. “So we do our best to make them feel appreciated by keeping them thoroughly updated about the powerful impact they are having and showing them how much they matter to us.” In turn, monthly donors tend to be dedicated supporters. “Protecting children - giving them opportunities to play, learn, feel safer, heal - is critical to us,” explained a survey respondent, expressing a commitment to children that UNICEF USA's Monthly Giving team sees every day.

    Supporters who sign up with UNICEF USA to give monthly automatically become members of the Guardian Circle, which affords them benefits, including:

    Annual statements to make tax time easier

    An easy-to-use donor access that simplifies modifying gift amounts, updating payment methods and making other changes, including the timing of donations with the option to cancel at any point

    Targeted communications in the form of monthly statements and a quarterly 8-page newsletter with stories from the field.

    A team available to answer questions via email or phone.

    “We have some donors who are on fixed income, others who can afford to make considerable monthly donations," says Coello. “Whether you give $5 or $700 a month, you are super important to us. What's important is that they all really want to give and help children. And that's amazing.”

    It can be time-consuming and difficult to track charitable donations. At end of year, Guardian Circle monthly supporters receive one statement that makes filing tax returns easier - and it's always delightful to see how much good has been done for the world's most vulnerable(受伤害的)children.

    American schools do not have separate classes for boys and girls. If boys want to cook or to sew, they can learn these things in classes that are no longer just for girls. If girls want to repair cars, they can now learn this in school. Most students like to have boys and girls on the same baseball team.

    Many boys and girls dress alike in school. They wear blue jeans and sport shirts. Some have long hair and some have short hair. Sometimes a boy has longer hair than a girl.

    Even the language is different. Students learn to say fire fighter instead of fireman, police officer instead of policeman, and letter carrier instead of mailman. A person does not need to be a man to fight a fire or to deliver the mail.

    Most people think that these changes are great. They give all people an equal chance to be happy and to do what they want to do with their lives. Fathers like to tell their sons that they can grow up to be president. Today, mothers can tell the same things to their daughters.

    Have you ever heard of agritourism where you can experience farm life? If not, Dr. Cindy Ayers-Elliott will tell you the real story of Foot Print Farms.

    The original concept of building Foot Print Farms was simple. When Ayers-Elliott returned to her hometown after graduation, she didn't have to look any further than her state's alarming health statistics to find a mission. Everywhere she turned, there were reports of high blood pressure, diabetes, obesity and heart disease. "The problem was already identified." explains Ayers-Elliott. "Too many Mississippians were seriously unhealthy and it didn't take research to see that. And many of the state's greatest health challenges could directly result from poor diet. "

    These days, Foot Print Farms, which started with a few raised beds of herbs and vegetables, is making fresh, naturally grown food. "When speaking of the key to my success, the co-op model works because we share the work and rewards," notes Ayers-Elliott. "A perfect example is the Wingfield High School football team. To earn the money for equipment and other items, players committed to working five hours a week on the farm, and by the end of the summer they had produced 1, 000 melons and the profits from their sales helped to buy weights, T-shirts, sweat suits and pregame meals. But the lessons they learned about the rewards of hard work and working together to accomplish something were even more valuable products of their efforts."

    "It' s a model that can easily be learned in other places and I' m looking forward to seeing some of our current partners do just that——to take what they have learned here and spin it off in other communities," Ayers-Elliott remarks. She is now looking forward to developing an agritourism aspect to the farm, where visitors can experience farm life, learn new skills and take with them seeds of inspiration they can sow in their own communities when they return home.

    I believe children have a very pure sense of humor. Well, I would like to share my experiences with you.

    The other day when I was out with a friend and her daughter Jane at a restaurant, Jane ordered an apple dessert, which was the most attractive dish in that restaurant. However, when she had a bite of the pie, she shouted loudly, "Mom, why does it look good but tastes like rubber?" My friend was uneasy. Then the waiter gave us another dish.

    A child can say funny things. I was at a friend's home for tea and her son, Mark, wanted her to get up. His mom replied, "I can't, because my foot has fallen asleep now." Little Mark then sang a song and asked, "Mom, will it wake up now?" We laughed together.

    The other day we were having an interesting conversation over lunch and my friend, an animal activist (积极分子) , was arguing with another group member. Her son Tommy suddenly stood up, “Mom, people should never be allowed to shoot extinct animals!” That was funny and the child did manage to turn the argument into a pleasant conversation.

    Well, children sometimes really surprise us. I think we can have a lot to learn from them. They can help us understand the simple world through their eyes.