The “swim-with-dolphins” tourist industry is becoming more popular every year with the increase of people's income. After all, it can cost a large amount of money to have this kind of holiday experience. So tour operators try to place eager swimmers as near as possible to the dolphins by trying to predict where the dolphins will be.

    Research has shown that while dolphins can move away if they do not want to interact (交流） with human swimmers, they do not like it at all if the swimmers slip into the water directly on top of them or if humans are in their path of travel. However, if swimmers enter the water to one side of them, the dolphins do not avoid the swimmers to the same extent.

    In all cases, the dolphins seem to have become more sensitive to the presence of the swimmers. For dolphins, swimming amongst or with humans is not necessarily a high priority. This research has shown that only 19% of any group of dolphins will participate in interaction. Young dolphins are the most likely to interact; they do seem curious about being with humans. It is believed that they see humans as “entertainment” and that the interaction is a new and unusual experience for them.

    It is frequently asked whether “swim-with-dolphins” tourism should be discontinued. The advice is that dolphins should be given enough periods of time throughout the day when they are not exposed to tourism. Permitted interactions should not be too disturbing to the dolphins since there could be mothers and calves (幼崽） present in dolphin groups. There should also be educational campaigns about the creatures and what is likely to cause danger to them.

    It is not easy to explain to someone that they cannot fulfill their lifelong dreams because the dolphins are resting, or that a mother dolphin and calf are in the area. But if we are to enjoy these remarkable animals and not just use them for our entertainment, then we must carefully monitor the “swim-with-dolphins” industry worldwide.

    These days, it seems that almost all of us are too serious. My older daughter often says to me, "Daddy, you've got that serious look again." Even those of us who are committed to non-seriousness are probably too serious. People are frustrated and anxious about almost everything—being five minutes late, witnessing someone look at us wrong or say the wrong thing, paying bills, waiting in line, overcooking a meal, making an honest mistake -- you name it, and we all lose perspective（理性判断）over it.

    The root of being anxious is our unwillingness to accept life as being different, in any way, from our expectation. Very simply, we want things to be a certain way but they're not a certain way. Life is simply as it is. Perhaps Benjamin Franklin said it best: "Our limited perspective, our hopes and fears become our measure of life, and when circumstances don't fit our ideas, they become our difficulties." We spend our lives wanting things, people, and events to be just as we want them to be—and when they're not, we fight and we suffer.

    The first step in recovering from over-seriousness is to admit that you have a problem. You have to want to change, to become more easygoing. You have to see that your own anxiety is largely of your own creation—it's made up of the way you have set up your life and the way you react to it.

    The next step is to understand the link between your expectations and your frustration level. Whenever you expect something to be a certain way and it isn't, you're upset and you suffer. On the other hand, when you let go of your expectations, when you accept life as it is, you're free.

    A good exercise is to try to approach a single day without expectation. Don't expect people to be friendly. When they're not, you won't be surprised or bothered; if they are, you'll be delighted. Don't expect your day to be problem-free. Instead, as problems come up, say to yourself, "Ah, another barrier to overcome." As you approach your day in this manner you'll notice how elegant life can be. Rather than fighting against life, you'll be dancing with it. Pretty soon, with practice, you'll lighten up your entire life. And when you lighten up, life is a lot more fun.

    Friends always ask why I, a middle-aged woman with no athletic talent, travel to perilous places—the jungles of Thailand or Borneo, for example, where the water is often unsafe and the food risky; places with infectious diseases, poisonous snakes and the wildest animals; some places where the locals are just a few generations past headhunting.

    I never know how to answer. My travel decisions assumed a new gravity nine years ago after I suffered a stroke. To prevent another stroke, my doctors told me, I'd have to take dangerously high levels of blood thinner (血液稀释剂) for the rest of my life and any travel would be risky.

    I had to think about what was important to me: family, of course, and friends. But then what? No matter how many times I thought about it, no bucket list was complete without travel. Then I had to decide how I might manage the risk. I had to decide how lucky I felt.

    My return to travel after my stroke came in baby steps. The first real test of my travel courage came nine months after my stroke when I joined my husband, Jack, on a business trip to China. After we'd toured the remains of a Tang dynasty temple on a high mountain, Jack wanted to ride down on a toboggan (长雪橇).

    Before the stroke it would've seemed like fun. But now? I hesitated. My mental klaxon (高音喇叭) screamed warnings about the consequences of a cut, a fall, and a crash. Then, gaining confidence from who knows where, I lowered myself carefully into the toboggan, which marked my adventure travel comeback.

    In the years since then, I've traveled about twenty-five percent of the time. Through it all, my lucks held out—no deadly falls, no car accidents or serious infections. For me, adventure travel is a risk worth taking. Travel broadens my world and keeps me connected to nature. What's more, saying "yes" to travel keeps me connected to myself.

    I was driving down the road the other day, listening to sweet music coming out of my car radio. My heart felt peaceful, my mind was clear, and my soul was full of love. Even with all its problems: life seemed good. Then the music stopped and the news came on. There was talk of another famous millionaire in drug rehab (康复) after an incident with the police. There was news on the murder of a poor man whose life was supposed to be changed after winning the lottery. There was even a discussion on how much greed and excess (放肆) had damaged our world.

    Every story seemed to point once again to the old saying that money can't buy happiness. Hearing them made me think of a movie I saw many years ago on Mother Teresa's home for the dying in India. What struck me most when I watched it wasn't the unbearable poverty there. It wasn't the sickness and suffering that the people there were going through. It was rather the peaceful smiles of love, kindness, and happiness that they shared with the Sisters and with each other. These people had nothing. Many were struggling at the end of death. Yet, they knew the simple truth that so many of us here are still learning: Joy is Free.

    We can have joy and spread joy every day of our life here. Don't love or admire dollar signs and think that money will bring you happiness then. Joy can't be purchased. It can't be owned. It can only be chosen and then given freely to others. In the eyes of eternity (永恒), money is only worthless paper. The only thing that matters is the love within you and the love that you give to the world. Make that your legacy (遗产) and your life will forever be rich in joy.

    People have been wondering why elephants do not develop cancer even though they have lifespans (寿命) that are similar to humans, jiving for around 50 to 70 years.

    Now scientists believe they know why. A team at the University of Chicago, US has found that elephants carry a large number of genes that stop tumors (肿瘤) developing. To be precise, they found 20 copies of an anti-tumor gene called TP53 in elephants. Most other species, including humans, only carry one copy.

    According to the research, the extra copies of the gene improved the animal's sensitivity to DNA damage, which lets the cells quickly kill themselves when damaged before they can go on to form deadly tumors.

    "An increased risk of developing cancer has stood in the way of the evolution of large body sizes in many animals," the study author Dr Vincent Lynch told The Guardian. If every living cell has the same chance of becoming cancerous (癌变的), large creatures with a long lifespan like whales and elephants should have a greater risk of developing cancer than humans and mice. But across species, the risk of cancer does not show a connection with body mass.

    This phenomenon was found by Oxford University scientist Richard Peto in the 1970s and later named "Peto's paradox (悖论)”". Biologists believe it results from larger animals using protection that many smaller animals do not. In the elephant's case, the making of TP53 is nature's way of keeping this species alive.

    The study also found that when the same genes were brought to life in mice, they had the same cancer resistance as elephants. This means researchers could use the discovery to develop new treatments that can help stop cancers spreading or even developing in the first place.

    "Nature has already figured out how to prevent cancer," said Joshua Schiffman, a biologist at the School of Medicine, University of Utah, US. "It's up to us to learn how different animals deal with the problem so that we can use those strategies to prevent cancer in people."

Max Du won the Canada-Wide Science Fair. His project is a drone (无人机) to save people who go into cardiac (心脏的) arrest. Max got the inspiration during Christmas break last year. "I got a toy drone from my parents, but I couldn't fly it because it is snowy." Max said. "So I played with it at home, and it got me thinking how a drone could be used as an indoor robot that could help people."

About 35, 000 people have cardiac arrests in Canada each year. Most of those happen outside of a hospital, of whom fewer than 10 percent survive. Max believed a drone could offer faster support and life-saving medicine, but he had to build it himself to know for sure.

Testing his drone took about six months. Max's parents had to deal with their son's constantly flying and crashing in the home. Every time Max would create an exciting innovation, such as an extendable arm, it would add extra weight to his drone, causing it to break apart. Then Max would have to buy all new parts. Max tested using more lightweight materials until his design was more balanced.

Through trial and error, the 14-year-old boy finally got it right. His drone can open a door handle, fly in the air and then land softly on the ground. A new extendable arm can be released to administer a shot or hand a patient lifesaving medicine. A built-in camera could directly conference with an emergency response team whose members could monitor the patient remotely.

Max plans on applying for a patent (专利) so he can make connections in the health-care industry to get it made for real. He's spent his summer learning about artificial intelligence at California's Stanford University as one of 32 kids selected worldwide. He'll head next to the University of Pennsylvania to take a college-level robotics class before returning to high school in September.