The human body is designed to move. But modern lifestyles and office jobs rarely give us the chance to move around. As we know, we're sitting while we're eating; we sit in the car and we sit while we watch TV. And many of us sit for many hours at work.

    New research shows that sitting less than three hours a day might extend your life by two years. Peter Katzmarzyk, a scientist at the University of Louisiana in the southern United States, says that sitting is ubiquitous in our lives, meaning it is something we do all the time, everywhere.

    However, Mr. Katzmarzyk says that does not mean you can sit for the rest of your waking hours. He also says you may exercise often, "We can't throw away physical activity. It's extremely important. We have 60 years of research showing us that."

    Mr. Katzmarzyk and his colleagues are part of a new generation of researchers studying how sitting all day affects length of life. "Studies that have assessed the relationship between sitting and mortality (死亡率) or television viewing and mortality are very rare. There's only been a few of them, actually five or six now, in the last four or five years." They found that cutting television time to less than two hours a day could add one point four years to life.

    Luckily, change is already coming to some offices, especially in the design of desks. A "standing desk" lets people stand while they work. Another new design is called the "treadmill desk." A treadmill is an exercise machine that lets you walk in one place. Even some U.S. schools are beginning to experiment with desks that are part bicycle to keep children moving. That's one of the strategies that many companies are using now.

    Mr. Katzmarzyk also says studying this problem has inspired his team to make a few changes in their own lives.

    Honey from the African forest is not only a kind of natural sugar, it is also delicious. Most people, and many animals, like eating it. However, the only way for them to get that honey is to find a wild bees nest(巢）and take the honey from it. Often, these nests are high up in trees, and it is difficult to find them. In parts of Africa, though, people and animals looking for honey have a strange unexpected helper—a little bird called a honey guide.

    The honey guide does not actually like honey, but it does like the wax（蜂蜡） in the beehives (蜂房).

    The little bird cannot reach this wax, which is deep inside the bees' nest. So, when it finds a suitable nest, it looks for someone to help it. The honey guide gives a loud cry that attracts the attention of both passing animals and people. Once it has their attention, it flies through the forest, waiting from time to time for the curious animal or person as it leads them to the nest.

    When they finally arrive at the nest, the follower reaches in to get at the delicious honey as the bird patiently waits and watches. Some of the honey and the wax，always falls to the ground, and this is when the honey guide takes its share.

    Scientists do not know why the honey guide likes eating the wax, but it is very determined in its efforts to get it. The birds seem to be able to smell wax from a long distance away. They will quickly arrive whenever a beekeeper is taking honey from his beehives, and will even enter churches when beeswax candles are being lit.

    Life in the summertime is often full of pests. Like most Long Island homeowners, I want to ensure my suburban life with pest-free living. So it was with wide-eyed wonder that I greeted the smiling exterminator (灭虫者) who rang my bell.

    “We'll be serving your neighbors, Mike and Sarah (I'm not familiar with either one by name),” he waved in the other direction. “Since we'll have a team here tomorrow, we're offering a discount.” He came out with numbers beginning from $299 then in seconds to $89.

    “You've probably been seeing the ant hills around.” he moved toward my front walkway and lawn. “And have you seen the bees that dig nests in the ground?” he continued with his head shaking up and down pushing me to do the same.

    “What we do is spray three feet out from your foundation and three feet up.” As he was talking, and without breaking eye contact, he opened his iPad cover and began operating at the screen to show me frightening images. “It also kills other pests, like spiders. It is the best pesticide (杀虫剂),” he said, pausing for effect.

    He then went into soft talk to close the deal, correctly foreseeing that I would be concerned about safety and the environmental impact on my vegetable garden, plants and our little patch of planet here on Long Island. “The products are environmentally responsible, safe with children and pets,” he said.

    I'm unkind when it comes to unwanted visitors entering on my out-of-doors moments. Any insect found in my house or on my deck is bound to be poisoned or pancaked.

    Unfortunately for the exterminator, just as I was considering making an appointment, Billy, my fearless husband, pulled into our driveway, which made me ask for a business card out of politeness instead.

    When I was a very little child, I remember watching TV and seeing other children suffer in other parts of the world. I would talk to myself, "when I grow up, when I can become rich, I'll save kids all over the world."

    At the age of 17, I began my career here in America, and by 18, I started my first charity organization. I went on to team up with other organizations in the following years, and met, helped, and even lost some of the most beautiful souls, from six-year-old Jasmina Anema who passed away in 2010 from leukemia (白血病)—her story inspired thousands to volunteer as donors, to 2012 when my grandmother lost her battle with cancer, which is the very reason and the driving force behind the Clara Lionel Foundation (CLF). We're all human. And we all just want a chance: a chance at life, a chance in education, a chance at a future, really. And at CLF, our mission is to impact as many lives as possible, but it starts with just one.

    People make it seem too hard to do charity work. The truth is, you don't have to be rich to help others. You don't need to be famous. You don't even have to be college-educated. But it starts with your neighbor, the person right next to you, the person sitting next to you in class, the kid down the block in your neighborhood. You just do whatever you can to help in any way that you can. And today, I want to challenge each of you to make a commitment to help one person, one organization, one situation that touches your heart. My grandmother always used to say, "If you've got a dollar, there's plenty to share."

    In 1972, a social worker named Sanjit Bunker Roy founded Barefoot College in Tilonia, Rajasthan. Today the college trains women from villages for six months to build and maintain solar panels and other instruments. Barefoot College also offers education to the younger generation both during the day and at its solar bridge schools that meet by lamplight at night.

    The philosophy of Barefoot College is largely inspired by the principles of Gandhi, starting with equality beyond caste (种姓), gender or religion. As a matter of fact, women are prioritized (优先考虑) as an underserved population that is essential to bringing villages together. Another central principle of the college is self-reliance, teaching students to support and think for themselves.

    After the college's female students have completed their half-year of training, they return to their villages where they wait for solar panel parts to arrive from the college. Once they have all the pieces they need, they construct the panels and begin collecting solar energy. For each village, the college also provides solar lamps. Villagers can, in addition, order parts for other solar-powered devices, such as water heaters and cooking stoves. Once assembled, they and the lamps are powered by the solar panels.

    The effect on the villages is huge. Before the solar panels and lamps arrived  villagers had only candles to light their homes. This prevented adults from doing serious work at night, and it made studying difficult for children as well. As for physicians, they had difficulty treating patients and performing operations at night because they had to rely on flashlights.

    Now there is power for not only the electrical appliances that the college provides but also devices like televisions, radios and computers. For the first time, the villagers can even connect to the world through the Internet.

Most people assume that the human brain is set on "automatic"—that means it learns all by itself. But this isn't always true. We need to train ourselves to be better learners—to actively take part in the learning process and to reflect on what we have learnt. These kinds of learning behaviours are called "active learning". I suggest doing four things to take an active role in your learning.

Listen to the outer voice

There are two kinds of voices: the inner voice and the outer voice. Your inner voice expresses your personal opinions, while the outer voice tells you about opinions from what you hear or read. Although your inner voice can be useful, it can also get in the way of learning. If you keep paying too much attention to it, you risk missing important information. Instead, active learners are open-minded and focus on what the speaker/ write is saying, not on what their brain is saying in the background. In this way, they are in a better position to make decisions.

Ask questions

Asking questions is the easiest way to promote active learning. When you get information from someone, from books or the Internet, ask two, three, even five question about the topic. The answers will lead you to further learning, and the very act of working out questions will help you to achieve a higher level of understanding about the topic. In short: Do not stop being curious.

Get to the truth

Active learners do not accept everything they learn. They attempt to find the truth at the heart of each idea. Even when an idea sounds entirely unlikely, there may be an aspect of it that is based on truth. So if someone says that dinosaurs still exist today, think about why they believe this. Where does the idea come from? Do they have enough data to support their views? If you try to find out the source of an idea, no matter how crazy it seems, you will increase your chance of learning something.

Focus on the message

Many people miss out on learning opportunities because they let their feelings get in the way. They refuse to learn or ignore what is said because of who the speaker/ writer is. It is true that we cannot help disliking some people —this is human nature, after all. But do not forget you can still learn from them. Active learners do not judge people based on firs impressions or personal feelings. Instead, they separate the message from the message. This goes the other way as well—do not just assume that some people are always right because of who they are or just because they are your friends.