Following news of the potential for life on the recently-discovered TRAPPIST-1 system, there may be another competitor ready to take its place.

    With the help of the Cassini spacecraft, NASA (National Aeronautics and Space Administration) scientists have picked up the first evidence that chemical reactions are taking place deep below the surface of Enceladus, Saturn's (土星的) sixth-largest moon. This means that there could be life in Enceladus' warm underground seas.

    An early study found that liquid oceans exist miles below Enceladus' surface. But to reveal what is happening down there, scientists must rely on the plumes (股) of water that spray (喷射) through cracks in Enceladus' icy surface. In October 2015, NASA sent Cassini into a deep dive into one of the plumes.

    Cassini's findings, published on April 13 in the journal Science, showed that hydrogen (氢) not only exists on Enceladus, but is also responsible for a chemical reaction between hot rocks and water in the ocean beneath its surface.

    This same process on Earth provides energy for entire ecosystems around volcanic vents (火山口). There, tiny creatures are able to survive without sunlight, using hydrogen and carbon dioxide as fuel in a process known as “methanogenesis (甲烷生成)”.

    The discovery of this chemical energy source on Enceladus means it could be a very good candidate to host life.

    “Confirmation (确认) that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone (里程碑) in our search for habitable (可居住的) worlds beyond Earth,” Linda Spilker, Cassini project scientist at NASA, told the Daily Mail.

    Alien life was once only thought possible on habitable planets within the “Goldilocks zone” – far enough from our sun not to be a fireball, but not so far as to be freezing.

    Research on Enceladus is still in its early stages, but the recent findings have important meanings for future exploration.

    “At present, we know of only one genesis (诞生) of life, the one that led to us,” David Rothery, professor of planetary geosciences (行星与地球科学) from the Open University in the UK, told The Telegraph.

    “If we knew that life had started independently in two places in our solar system, then we could be pretty confident that life also got started on some of the tens of billions of planets and moons around other stars in our galaxy,” he said.

    The World Health Organization says the widespread use of sugar in food products and drinks is a major concern in many areas. So WHO officials are calling on governments to require taxes on sugary drinks in an effort to limit their usage and popularity. The officials believe the taxes also would reduce the risk of health problems resulting from obesity.

    Obesity is a condition in which the body stores large, unhealthy amounts of fat. Obese individuals are considered overweight. A new report says that in 2014 more than one-third of the adults in the world were overweight, and 500 million were considered obese. The United Nations agency estimates that in 2015, 42 million children under age 5 were either overweight or obese. It says that number represents an increase of about 11 million during the past 15 years. Almost half of these boys and girls live in Asia and one-fourth in Africa.

    The U.N. agency blames unhealthy diets for a rise in diabetes cases. There are 422 million cases of the disease worldwide. WHO says 1.5 million people die from it every year. It says the use of sugar in food products, like sugary drinks, is a major reason for the increase in rates of obesity and diabetes.

    Temo Waqanivalu is with the agency's Department for the Prevention on Non-Communicable Diseases. He told VOA hat taxing sugary drinks would reduce consumption and save lives. Waganivalu noted that Mexico enacted a 10 percent tax on sugary drinks in 2014. He said by the end of the year, there was a 6 percent drop in the consumption of such drinks. Among poor people, the number of people who consumed sugary drinks dropped by 17 percent.

    The WHO says people should limit the amount of sugar they consume. It says they should keep their sugar intake to below 10 percent of their total energy needs, and reduce it to less than 5 percent for improved health.

Senses That Work Together

    When we think about how our senses work, we usually imagine them operating separately: you sniff a flower, and the smell is delivered uninterrupted from nose to brain. However, it's more complex than that. Most evidence for cross modal perception (知觉) comes from studies into sound and vision (视觉). But research that shows other senses crossing over is coming out all the time, and it seems that even sound and smell sometimes form an unlikely pairing.

    When New York researchers, Daniel Wesson and Donald Wilson, tried to find out the truth about a "mysterious” area of the brain called the olfactory tubercle, they had to deal with this fact. Originally, they only intended to measure how olfactory tubercle cells in mice responded to smell. But during testing, Wesson noticed that every time he put his coffee cup down, the mouse cells jumped in activity. In fact, the olfactory tubercle is well-placed to receive both smell and sound information from the outside world. Later they found that among separate cells, most responded to a smell but a significant number were also active when a sound was made. Some cells even behaved differently when smell and sound were presented together, by increasing or decreasing their activity.

    Of course, mice aren't people, so research team has been carrying out further experiments. They pulled together a group of people and gave them various drinks to smell. Participants were asked to sniff the drinks, and then match them to appropriate musical instruments and produce the notes at different levels. The results were interesting: piano was regularly paired with fruity fragrances; strong smells sounded like the instruments that are made of metal.

    Further research found that listening to different sounds can change your perceptions. Studying taste this time, the team ordered some special toffee (太妃糖) and put together “soundscapes” corresponding to bitterness and sweetness. Participants tasted similar pieces of toffee while listening to each soundscape, and found the toffee more bitter or sweeter, depending on which soundrack they were listening to.

    Studies like this are helping scientists correctly describe our understanding of the senses, and how the brain combines them with its advantage. The consequences are worth considering. Could we see musicians work together with chefs to produce sound-improved food and drink? Will you be ordering a coffee with a soundrack to bring out your favorite smell? Come to think of it, that could be one thing you hope coffee shop chains don't get round to.

    Failure is probably the most exhausting experience a person ever has. There is nothing more tiring than not succeeding.

    We experience this tiredness in two ways: as start-up fatigue(疲惫) and performance fatigue. In the former case, we keep putting off a task because it has either too boring or too difficult. And the longer we delay it, the more tired we feel.

    Such start-up fatigue is very real, even if not actually physical, not something in our muscles and bones. The solution is obvious though perhaps not easy to apply: always handle the most difficult job first.

    Years ago, I was asked to write 102 essays on the great ideas of some famous authors. Applying my own rule, I determined to write them in alphabetical(按字母顺序), never letting myself leave out a tough idea. And I always started the day's work with the difficult task of essay-writing. Experience proved that the rule works.

    Performance fatigue is more difficult to handle. Though willing to get started, we cannot seem to do the job right. Its difficulties appear so great that, however hard we work, we fail again and again. In such a situation, I work as hard as I can-then let the unconscious take over.

    When planning Encyclopaedia Britannica (《大英百科全书》), I had to create a table of contents based on the topics of its articles. Nothing like this had ever been done before, and day after dat I kept coming up with solutions, but none of them worked. My fatigue became almost unbearable.

    One day, mentally exhausted, I wrote down all the reasons why this problem could not be solved. I tried to convince myself that the trouble was with the problem itself, not with me. Relived, I sat back in an easy chair and fell asleep.

    An hour later, I woke up suddenly with the solution clearly in mind. In the weeks that followed, the solution which had come up in my unconscious mind provided correct at every step. Though I worked as hard as before, I felt no fatigue. Success was now as exciting as failure had been depressing.

    Human beings, I believe must try to succeed. Success, then, means never feeling tired.

    At first, Michael Surrell didn't see the black smoke or flames shooting from the windows of his neighbors' home. He and his wife had just parked around the corner from their own house in Allentown, Pennsylvania, when they got a call from one of his daughters, "The house next door is on fire!" He went to investigate. That's when he saw two women and a girl hysterical (歇斯底里的)on their porch.

    "The baby's in there!" one of the women cried. Though the fire department had been called, Surrell, then 64, instinctively ran inside. "The baby" was 8-year-old Tiara Roberts, the woman's granddaughter and a playmate of Surrell's three youngest kids, then 8, 10, and 12. The other two on the porch were Tiara's aunt and cousin.

Entering the burning house was like "running into a bucket of black paint," Surrell says. The thick smoke caused him to stumble blindly around, burned his eyes, and made it impossible to breathe. The conditions would have been hazardous for anyone, but for Surrell, who has chronic obstructive pulmonary disease (慢性阻塞性肺疾病), they were life-threatening. He was the last person who should have run into a burning building— he has lung disease. But that didn't stop him.

    After a few minutes in the smoke filled house, he retreated outside to catch his breath. "Where is Tiara?" he asked desperately." The second floor." her aunt shouted back.

    Surrell knew he couldn't hold his breath for long. So he uttered a little prayer, "Well, Lord, this is it. You gotta help me, because I'm not coming out without that little girl." Taking a deep breath, he went in a second time.

    The darkness was overwhelming. Yet because the house had a similar layout to his, he found the stairs and made it to the second floor. He turned to the right and was met by intense heat. He was already out of breath.

    "Baby girl, where are you?" His throat and lungs burned as if he'd inhaled fire instead of the smoke and soot in the air. Every blink stung his eyes. All he could hear was the crackling and popping of burning wood. ①.Still unable to see, Surrell fell to his knees on the hot wood floor. He crawled toward the sound, feeling around for any sign of the girl. An ominous thought crossed his mind: I'm probably gonna die up here.

    Finally he touched something. A shoe, then an ankle. He pulled Tiara toward him. ②Her body was limp and she wasn't breathing. He scooped her into his arms and stood. He felt the heat of the flames on his cheeks. Turning, he fought through the smoke and ran blindly into the blackness. The next thing he knew, he was at the front door, then outside. Surrell put Tiara down on the porch.

    ③. A voice told him, "You have to breathe for her." He started CPR -the first time he'd ever done so. The women stood behind him, praying silently. Soon a soot-filled cough came from Tiara's throat. Surrell gave five more breaths. She coughed again. Her eyes flickered. He gave one final breath. She opened her eyes and took a breath on her own.

    ④.Their eyes met. Surrell hugged her tight and said, "Uncle's got you.^" Soon after, his throat closed off.

    Surrell woke up in the hospital a couple of days later, having suffered severe burns to his windpipe and the upper portion of his lungs. He spent over a week in the hospital. Tiara was released from the hospital after a few days. The fire exacerbated Surrell's pulmonary condition, and he feels the effects even two years later. As a result, he takes extra medication that helps open his airways. "It's a small price to pay," he says. "I'd do it again in a heartbeat. Wouldn't give it a second thought."

An airline passenger ensured a 20-year-old man was reunited with his lost wallet-along with a little extra something to make up for their time apart.

Hunter Shamatt first lost his wallet while he was on a Frontier Airlines flight from Omaha to attend his sister's wedding in Las Vegas earlier this month. On realizing his wallet was lost, he contacted the airline to see if anyone had turned it in—but to no avail. Since the wallet contained his ID, a signed paycheck, his debit card and $60 in cash, he "feared the worst".

Shortly after the flight, however, Hunter was shocked to receive a package in the mail from an unknown sender. Inside was his wallet-along with an additional $40 in cash.

"Found this on a Frontier flight from Omaha to Denver-row 12, seat F stuck between the seat and wall," read a letter in the package. "Thought you might want it hack. All the best. PS: I rounded your cash up to an even $100 so you could celebrate getting your wallet hack. Have fun!"

Hunter's mother, Jeannie, posted a photo of the letter to social media in hopes that they would be able to track down the sender and thank them for their kindness. All they had to go on was that the letter was sent from Applied Underwriters in Omaha and the sender's initials were signed: "T.B".

The Good Man was later identified as Todd Brown, a father-of-five who was delighted at the chance to "have a little fun" with helping out a hard-working stranger. Brown says that he often tries to do good deeds without any recognition, thus why he didn't sign his full name on the letter, but Jeannie later insisted on praising the Nebraska native on social media.

"I try to teach my children to do the right things in life, help people when you can despite the outcome," she wrote on Facebook. "This story is more about restoring faith in people than anything".