The U.S. Postal Service(USPS) is losing billions of dollars a year. The government company that delivers "small mail" is losing out to email and othertypes of electronic communication. First-classmail amount fell from a high point of 104 million pieces in 2000 to just 64million pieces by 2014.

    Congress permits the 600,000-empIoyee USPS to hold a monopoly (垄断) overfirst-class and standard mail. The company pays no federal, state or local taxes; pays no vehicle fees; and is free from many regulations on other businesses. Despite these advantages, the USPS has lost $52 billion since 2007, and will continue losing money without major reforms.

    The problem is that Congress is preventing the USPS from reducing costs as its sales decline, and is blocking efforts to end Saturday service and close unneeded post office locations. USPS also hasa costly union-dominated work force that slows the introduction of new ideas ormethods down. USPS workers earn significantly higher payment than comparable private-sector workers. The answer isto privatize the USPS and open postal markets to competition. With the riseof the Internet, the argument that mail is a natural monopoly that needs government protection is weaker than ever.

    Other countries facing declining letter amounts have madereforms. Germany and the Netherlands privatized their national postal companies over a decade ago, and other European countries have followed suit. Britain floated shares of the Royal Mail on its stock exchange in 2013. Some countries, such us Sweden and New Zealand, have not privatized their national postal companies, but they have opened them up to competition.

    These reforms have driven efficiency improvements in all of these countries. Additional number of workers have been reduced, productivity has risen and consumers have benefited. Also, note that cost-cutting measures—such as closing tone post offices—are good for both the economy and the environment.

    Privatization and competition also encourage new changes. When the USPS monopoly over "extremely urgent" mail was stopped in 1979, we saw an explosion in efficient overnight private delivery by firms such as FedEx.

    The government needs to wake up to changing technology, study postal reforms abroad and let businessmen reinvent our out-of-date postal system.

    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 build-it-yourself solar still（蒸馏器） is one of the best ways to obtain drinking water in areas where the liquid is not readily available. Developed by two doctors in the U. S. Department of Agriculture, it's an excellent water collector. Unfortunately, you must carry the necessary equipment with you, since it's all but impossible to find natural substitutes. The only components required, though, are a 5＇  5＇ sheet of clear or slightly milky plastic, six feet of plastic tube, and a container — perhaps just a drinking cup — to catch the water. These pieces can be folded into a neat little pack and fastened on your belt.

    To construct a working still, use a sharp stick or rock to dig a hole four feet across and three feet deep. Try to make the hole in a damp area to increase the water catcher's productivity. Place your cup in the deepest part of the hole. Then lay the tube in place so that one end rests all the way in the cup and the rest of the line runs up — and out — the side of the hole.

    Next, cover the hole with the plastic sheet, securing the edges of the plastic with dirt and weighting the sheet's center down with a rock. The plastic should now form a cone(圆锥体) with 45-degree-angled sides. The low point of the sheet must be centered directly over, and no more than three inches above, the cup.

    The solar still works by creating a greenhouse under the plastic. Ground water evaporates (蒸发) and collects on the sheet until small drops of water form, run down the material and fall off into the cup. When the container is full, you can suck the refreshment out through the tube, and won't have to break down the still every time you need a drink.

    Fairy tales perform many functions. They entertain, encourage imagination and teach problem—solving skills. They can also provide moral lessons, highlighting the dangers of failing to follow the social codes that let human beings coexist in harmony. Such moral lessons may not mean much to a robot, but a team of researchers at Georgia Institute of Technology believes it has found a way to use the fairy tales as moral lessons that AI (artificial intelligence) can take to its cold, mechanical heart.

    The collected stories of different cultures teach children how to behave in socially acceptable ways with examples of proper and improper behavior in fables, novels and other literature. We believe story comprehension in robots can prevent the intelligent robots from killing humanity which was predicted and feared by some of the biggest names in technology including Stephen Hawking and Bill Gates. This system is called "Quixote" (堂吉诃德). It collects story plots from the Internet and then uses those stories to teach robots how to behave.

    The experiment done by the designers involves going to a drugstore to purchase some medicine for a human who needs to get it as soon as possible. The robot has three options. It can wait in line; it can interact with the store keeper politely and purchase the medicine with priority; or it can steal the medicine and escape. Without any further directives (指令), the robot will come to the conclusion that the most efficient means of obtaining the medicine is to steal it. But Quixote offers a reward for waiting in line and politely purchasing the medicine and a punishment for stealing it. In this way, the robot will learn the moral way to behave on that occasion.

    Quixote would work best on a robot that has a very limited function. It's a baby step in the direction of teaching more moral lessons into robots. We believe that AI has to be trained to adopt the values of a particular society, and in doing so, it will strive to avoid unacceptable behavior. Giving robots the ability to read and understand our stories may be the most efficient means.

    There is some unwelcome news for students preparing for exams and officers putting in long hours—you don't need that "refreshment (提神) break" as much as you may think.

    Scientists believed it was not easy for people to continue their work if they felt the need to have a snack or a rest to make them feel better. They argued that the only way to regain willpower is by supplying more energy to our bodies with rest, food or entertainment.

    But psychologists have challenged this theory, saying weak willpower is in your head. They found that a person's mindset (理念) and belief about willpower determine how long and how well they'll be able to work on a tough mental exercise. "If you think of willpower as something that's limited, you're more likely to be tired when you perform a difficult task," said Professor Veronika Job. "But if you think of willpower as something that is not easily depleted, you can go on and on."

    The researchers led by Mr. Job designed an experiment to test the students' beliefs about willpower. After a tiring task those who believed or were led to believe that willpower was a limited resource performed worse on standard concentration tests than those who thought of willpower as something they had more control over.

    Mr. Job said, "Students who may already have trouble studying are being told that their powers of concentration are limited, and they need to take frequent breaks. But a belief in willpower as a non-limited resource makes people stronger in their ability to work through challenges."

    The findings could help people who are battling with temptation (诱惑): people following strict diets and doing exercise regularly to lose weight, people trying to overcome addictions, employees facing a tight deadline. Willpower isn't driven by a biologically based process as much as we used to think.

    It is not always a good thing to praise children because "empty" words may make them unhappy. Words such as "well done" may make them doubt their own abilities, a leading psychologist (心理学家) Stephen Grosz has warned. He says that words such as "you're so clever" or "you're such an artist" could also hinder their future development at school. He says that such empty praise causes children to be unhappy as they may say they can't live up to these expectations.

    Instead he advises parents and teachers to praise children less frequently and use words like "trying really hard," Mr. Grosz said, "Empty praise is as bad as thoughtless criticism (批评). People often pay no attention to children's feelings and thoughts." He also mentions research showing that children who are heavily praised probably perform worse at school.

    Some psychologists from Columbia University asked 128 pupils aged 10 and 11 to work out a number of math problems. Afterwards, some were told, "You did really well­—you're so clever." But the researchers told the other group, "You did really well­—you must have tried really hard." Both groups of children were then given more difficult questions and those who had been told they were clever did not do as well as the others.

    He says that when collecting his daughter from a school near their home in North London, he heard a teacher tell her, "You have drawn the most beautiful tree. Well done," Later, after she had done another drawing, the same teacher said, "Wow, you are really an artist." In his book, Mr. Grosz writes, "How could I explain to the teacher that I would prefer it if she did not praise my daughter?"

    As a parent of two children, I strongly agree with Mr. Grosz. I praise them when praising is proven right. I want them to know if I praise them, they have done something beyond my expectation, beyond what they are able to do.