Dolphins(海豚) live in a dark underwater world. It's often impossible to see each other or anything else around them, so sound plays an important role in their survival. To communicate with each other, dolphins produce all kinds of sounds.

    Only other dolphins understand what the sounds mean. Scientists haven't uncovered their secret communication, except for one kind of whistle. It might last less than a second, but this whistle is a big deal. Why? Because these whistles are actually names of dolphins - and every dolphin has one. Scientists call these sounds a “signature whistle.” When other dolphins hear the whistle, they know which dolphin is calling.

    Dolphins often hunt by themselves but still need to stay connected to the group. Since they can't always see each other, dolphins use their signature whistles to check in with other dolphins hundreds of yards away. “In coastal areas, dolphins exchange whistles even when they're a third of a mile apart,” says Greg Campbell, who studies animals. That means dolphins shout out to group members that might be nearly five football fields away.

    What's amazing is who names the baby dolphin. Not the mother. Not an auntie dolphin or another group member. Scientists believe the baby dolphin itself comes up with the signature whistle. Like human babies, a baby dolphin plays with sounds throughout its first year. While testing its sound skills, a baby dolphin is doing something amazing. It's creating or figuring out its signature whistle. How or why it chooses its signature whistle is not clear. Studies show that most of the time the signature whistle is nothing like its mother's or group members' whistles.

    When the baby dolphin is about a year old, its signature whistle is set. It repeats it often so the other dolphins learn to recognize it.

    Deciphering(破译) dolphin names is just the beginning of figuring out what dolphins communicate about. Do they chat about sharks? Discuss the tides? Maybe they even have a name for people. Someday scientists are to decipher the rest of dolphins' communication.

    After a year of examining many studies concerning whether homework is effective, NYC P. S. Elementary School decided that math worksheets and essay assignments were actually a waste of time. In February, Principal Jane Hsu sent a letter to parents stating that the Pre-K(学前班) through fifth grade students wouldn't be given any traditional homework to encourage kids to free time for reading, playing outside, or doing activities they enjoy.

    “The negative effects of homework have been well established.” Hsu wrote in a note to parents. “They include, children's frustration and exhaustion, lack of time for other activities and family time and, sadly for many, loss of interest in learning.”

    Some parents, however, disagree with the policy change, believing that a lack of focus will cause children to fall behind. Homework has been part of education from the beginning, and has increased in amount in recent years.

    Hsu's advice that children should read and spend time with their families has upset some parents to the point of considering pulling their children out of the school. This group feels that homework gives children a goal to work toward. Others feel so strongly about the importance of homework that they have begun giving their own homework to their children.

    An Australian Childhood Foundation survey finds that 71% of Australian parents feel they don't spend enough quality time with their children mainly because of the time spent running the household or the time spent helping with homework. Education experts in Australia are saying that parents should stop helping. Doing so will give kids more independence, give parents more free time, and help reduce the number of arguments caused by homework in the family.

    While some research suggests that homework has little academic benefit for elementary students, other researches show homework can help kids develop independence, and confidence. It can also contribute to a sense of belonging or control over their lives. When parents try to help their children with homework, the assistance can take away that feeling and can also make working parents more tired.

    This is the incredible school where the headteacher's unique dedication to handwriting practice means EVERY pupil is ambidextrous.

Only ten percent of the population are left-handed, and only ONE percent can write with both hands. But all 300 students at Veena Vandini School in India can write with both their left and right hand, with some able to do both at the same time—in different languages.

    Every 45-minute lesson features 15 minutes devoted to handwriting practice, to make sure all students at the remote rural school have the skill.

    The school, which was founded in 1999, is located in a remote area, in Singrauli district, Madhya Pradesh. School founder and former solider Vp Sharma said he was inspired to demand the lessons by India's first president.

     “I read in a magazine that Dr Rajendra Prasad used to write with both hands. This inspired me to give it a try. Later, when I launched my school at my native village, I tried training the students.

     “We began training students from standard I and by the time they reach standard III, they were comfortable writing with both the hands. Students of standard VII and VIII can write with speed and accuracy. Further, they can write two scripts simultaneously, one with each hand.

     “Students also know several languages, including Urdu.”

    Mr Sharma said their unique dedication to handwriting led South Korean researchers to visit and study the pupils two years ago, to find out more about ambidexterity.

    When you go to the doctor, you like to come away with a prescription．It makes you feel better to know you will get some medicine. But the doctor knows that medicine is not always needed. Sometimes all a sick person needs is some reassurance that all will be well. In such cases the doctor may prescribe a placebo.

    A placebo is a sugar pill, a harmless shot, or ail empty capsule. Even though they have no medicine in them, these things seem to make people well. The patient thinks it is medicine and begins to get better. How does this happen?

    The study of the placebo opens up new knowledge about the way the human body can heal itself. It is as if there was a doctor in each of us. The doctor will heal the body for us if we let it. But it is not yet known just how the placebo works to heal the body. Some people say it works because the human mind fools itself. These people say that if the mind is fooled into thinking it got medicine, then it will act as if it did, and the body will feel better.

    Placebos do not always work. The success of this treatment seems to rest a lot with the relationship between the patient and the doctor. If the patient has a lot of trust in the doctor and if the doctor really wants to help the patient, then the placebo is more likely to work. So in a way, the doctor is the most powerful placebo of all.

    A placebo can also have bad effects. If patients expect a bad reaction to medicine, then they will also show a bad reaction to the placebo. This would seem to show that a lot of how you react to medicine is in your mind rather than in your body. Some doctors still think that if the placebo can have bad effects it should never be used. They think there is still not enough known about it.

    The strange power of the placebo does seem to suggest that the human mind is stronger than we think it is. There are people who say you can heal your body by using your mind. And the interesting thing is that even people who swear this is not possible have been healed by a placebo．

    Tim Richter and his wife, Linda, had taught for over 30 years near Buffalo, New York – he in computers, she in special education. "Teaching means everything to us," Tim would say. In April 1998, he learned he would need a heart operation. It was the kind of news that leads to some serious thinking about life's purpose.

    Not long after the surgery, Tim saw a brochure describing Imagination Library, a program started by Dolly Parton's foundation (基金会) that mailed a book every month to children from birth to age five in the singer's hometown of Sevier, Tennessee. "I thought, maybe Linda and I could do something like this when we retire," Tim recalls. He placed the brochure on his desk, "as a reminder."

    Five years later, now retired and with that brochure still on the desk, Tim clicked on imaginationlibrary.com. The program had been opened up to partners who could take advantage of book and postage discounts.

    The quality of the books was of great concern to the Richters. Rather than sign up online, they went to Dollywood for a look-see. "We didn't want to give the children rubbish," says Linda. The books – reviewed each year by teachers, literacy specialists and Dollywood board members – included classics such as Ezra Jack Keats's The Snowy Day and newer books like Anna Dewdney's Llama Llamaseries.

    Satisfied, the couple set up the Richter Family Foundation and got to work. Since 2004, they have shipped more than 12,200 books to preschoolers in their area. Megan Williams, a mother of four, is more than grateful: "This program introduces us to books I've never heard of."

    The Richters spend about ＄400 a month sending books to 200 children. "Some people sit there and wait to die," says Tim. "Others get as busy as they can in the time they have left."

    I first began experiencing anxiety and depression at the age of 14, after being bullied (欺凌) at school for years. While at first anxiety and depression would come and go, it eventually became a constant part of my life.

    I was so eager to find the solution to overcoming my anxiety and depression that I tried everything from when I was in college to graduate school: mood-changing medication, special teas, yoga, anything I read about in books, and advice given by doctors. Despite this, I still felt I hadn't even come close to managing the problem.

    But one afternoon, my eyes fell upon an article in a magazine I was reading that talked about how dogs were able to help people with anxiety and depression. The very next day, I decided to get a dog—a corgi. When I brought my little corgi, Buddy, home. I didn't realize how much he would change my life. It didn't happen right away, however.

    Once the “puppy excitement” went away, my anxiety and depression came back as usual. One morning, I woke up with those familiar feeling again. I didn't want to get out of bed. I turned to pull the covers back over my head and give up. That's when I saw Buddy.

    Buddy started jumping all over me, licking my face, letting me know that it was time to go outside. It was as if he were saying, “There's no time to be sad; the world is amazing!” And for the first time in my life, my life was changing. I really was a new person. This was my new beginning.

    It's been more than a year since that day, and I've never spent another morning unable to get out of bed. I've not cried myself to sleep or spent my days stuck with fear and regret. Sure, I still have days when I feel sad or anxious. But with Buddy, my best friend, by my side, I've finally learned how to manage these feelings and emotions.