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．

    A team of UK researchers recently compared the performances of 120 women and 120 men in a computer test involving switching between tasks of counting and shape recognition.

    Men and women were equally capable when tasks were handled one at a time. But when the tasks were mixed up, there was a clear difference. According to the paper published in the journal BMC Psychology, both women and men slowed down and made more mistakes as the switching became more rapid. But the men were slower, taking 77 percent longer to answer, whereas women took 69 percent longer.

    To make the experiment more relevant to day-to-day life, researchers tried a second test. A group of women and men were given eight minutes to complete a series of everyday tasks, such as finding restaurants on a map, doing simple math problems, answering a phone call, or deciding how they would search for a lost key in afield. Once again, women outperformed men in the test, particularly in the key-searching task.

    “It suggests that in a stressed and complex situation women are more able to stop and think about what's going on in front of them,” researcher Keith Laws of the University of Hertfordshire, UK, told BBC News. “In contrast, men had a slight impulsiveness（冲动）, answering without giving much thought to their responses.”

    So where do women get the ability to keep organized under pressure better than men? Researchers believe that it has its roots in evolution. In early human communities, women had to keep an eye on children while cooking meals. Meanwhile, men only needed to focus on hunting.

    A recent study surveyed 5,000 British families about their experiences with volunteering and their mental health. Participants completed the same survey every two years from 1996 to 2008.

    About 20 percent of the survey participants reported doing regular unpaid work Researchers found that these volunteers also scored highest on their mental health scores. The two were linked so directly that the more a person volunteered, the happier they were.

    One could argue a chicken-and-egg theory: happier people are more likely to have the time, money, energy and resources to give back to others. But even when researchers adjusted for education, social class and total health, the link was there, suggesting that the mental increase came from volunteering and not the other way around.

    According to Dr. Stephen G. Post, author of The Hidden Gifts of Helping, when you help others, your brain releases feel-good chemicals, which can help cells repair themselves and grow. And this translates to better health.

    So volunteering can help improve both your physical and mental health—on one condition. You have to mean it. People who volunteered for "self-oriental" reasons, either because they were forced to do so for work or school or because they were trying to get away from problems in their lives, had a mortality（死亡率）risk that was similar to those who didn't volunteer at all. It was only when people were volunteering out of a true sense of sympathy that they saw any health benefits.

    So whether it's arranging books at the library or walking dogs at the animal shelter, find a cause that's important to you and give it a try. Volunteering is a good way to develop a sense of connection that not only helps your community, but may also be good for you.

    The best bikes for the beginners

    When it comes to purchasing your first bike, the choice is endless, making it tough to know what to go for. Here are the best buys on the market right now.

    Boardman CX Comp

    This is a cross-country bike, and it's so versatile（多用途的）that you can handle any terrain（地势）on it, making it a great choice for those wanting to try various cycling subjects. If you leave on the thick tires it comes with, it can ride on various paths and can even handle some less demanding mountain bike routes. Alternatively, put on thin, slick tires and treat it as a road bike. It has basket and comes with Shimano Sora gears, which are outstanding for its price.

    &650, Halfords

    Planet X RT-58 v2

    Planet C is based in Yorkshire, which means you'd probably have to buy this bike without seeing it. But it's worth it, because this is an excellent machine at a lower price. Planet X is a highly rated manufacture and this model comes with Shimano Sora gears.

    &439, Planet X

    Specialized Allez ES

    Specialized is one of the biggest and most popular brands in cycling, and this is its hugely popular primary road bike. It comes with solid components from front to back and you'll look great out on the road.

    &575, Evans Cycles

    Boardman Road Team Carbon

    If you can push budget further still, this bike is worth the extra investment. The frame is made entirely from carbon, which is lighter, faster and more comfortable than the composition metal models above and gives you an all-round more enjoyable ride. It also means that if you get really serious about cycling, you don't have to upgrade as quickly as you would with a cheaper bike.

&800, Halfords

    Darrell Blatchley, a marine biologist and environmentalist based in the Philippine city of Davao, received a call from the Philippines, Bureau of Fisheries and Aquatic Resources (渔业与水产资源局) early Friday morning reporting a death of a young whale.

    When the necropsy (尸检) was performed, Blatchley told NPR, he was not prepared for the amount of plastic they found in the whale's stomach. "It was full of plastic nothing but nonstop plastic." he said "It was filled to the point that its stomach was as hard as a baseball." That means that this animal has been suffering not for days or weeks but for months or even a year or more," Blatchley added.

    Blatchley is the founder and owner of the D'Bone Collector Museum, a natural history museum in Davao. In the coming days, the museum will display all the items found in the whale's system. Blatchley and his team work with the Bureau of Fisheries and Aquatic Resources and other organizations to assist in rescue and recovery of marine animals.

    "Within the last 10 years, we have recovered 61 whales and dolphins just within the Davao Gulf," he said. "Of them, 57 have died due to man whether they took plastic or fishing nets or other waste, or gotten caught in pollution — and four were pregnant."

    Blatchley said he hoped that the latest incident would launch the issue of plastic pollution in the Philippines and across the globe. "If we keep going this way, it will be more uncommon to see an animal die of natural causes than it is to see an animal die of plastic," he said.