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．

    Scientists have found living organisms(有机体) that could be 50,000 years old recently. The organisms were found in a hot, but beautiful cave system in Naica, Mexico. These ancient life forms can be seen only with a microscope, which proves they are probably microbes(微生物).

    Penelope Boston leads the Astrobiology Institute at NASA, the space agency of the United States. These ancient organisms are able to exist by eating minerals such as iron and manganese. If the findings are confirmed, they will show how microbes can survive in extreme conditions.

    Researchers have been studying ancient microbes for nine years. Forty different kinds of microbes and some viruses were found in the underground area this time. The genetic(基因的) structures of these organisms are different from those of their nearest relatives –viruses. That is similar to that humans are genetically different from mushrooms growing in forest. The caves in Naica are 800 kilometers deep. Before the miners began working in the caves, the area was isolated from the surface and the outside world.

    Some of the caves are as big as the large religious centers built during Europe's Middle Ages. There are crystals(晶体) covering the walls. Scientists must wear special clothing to keep cool. And the clothing keeps the crystals safe from human germs or other damage. The researchers could only work for about 20 minutes at a time before they have to go to a room that is 28 degrees Celsius to cool down.

    NASA officials would not let Boston share her findings with scientific experts until the last week's announcement. So scientists could not say much about the findings. But Norine Noonan, a biologist at the University of South Florida, said she believed them. “Why are we surprised?” Noonan asked, “As a biologist, I would say life on Earth is extremely tough and versatile.” “What's more, these organisms are not the oldest life forms on Earth. Scientists published studies about living microbes that may be 500,000 years old several years ago,” she added.

    By the mid-nineteenth century, the term “icebox” had entered the American language, but ice was still only beginning to affect the diet of ordinary citizens in the United States. The ice trade grew with the growth of cities. Ice was used in hotels, pubs, and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish, and butler. After the Civil War (1861-1865), as ice was used to refrigerate freight cars(货车), it also came into household use. Even before 1880, half the ice sold in New York, Philadelphia, and Baltimore, and one-third of that sold in Boston and Chicago, went to families for their own use. This had become possible because a new household convenience, the icebox, a precursor（前身）of the modem refrigerator, had been invented.

    Making an efficient icebox was not as easy as we might now suppose. In the early nineteenth century, the knowledge of the physics of heat, which was essential to a science of refrigeration, was undeveloped. The common belief that the best icebox was one that prevented the ice from melting was of course mistaken, for it was the melting of the ice that performed the cooling. Nevertheless, early efforts to economize ice included wrapping the ice in blankets, which kept the ice from doing its job. Not until near the end of the nineteenth century did inventors achieve the delicate balance of insulation(绝缘) and circulation needed for an efficient icebox.

    But as early as 1803, an intelligent Maryland farmer, Thomas Moore, had been on the right track. He owned a farm about twenty miles outside the city of Washington, for which the village of Georgetown was the market center. When he used an icebox of his own design to transport his butter to market, he found that customers would pass up the rapidly melting butter of his competitors to pay an extra price for his butter, still fresh and hard in neat, one-pound bricks. One advantage of his icebox, Moore explained, was that fanners would no longer have to travel to market at night in order to keep their produce cool.

    This is a true story that happened in Japan. In order to repair the house, a Japanese tore open the walls. Japanese houses normally have an empty space between the wooden walls. When pulling down the walls, he found that there was a lizard（蜥蜴）staying there because a nail（钉子）from outside was hammered into one of its feet. He saw this, feeling pity and curious. When he checked the nail, he found it was nailed 10 years ago when the house was first built.

    What happened? The lizard had survived in such a position for 10 years! It has been in a dark wall partition（夹层）for 10 years without moving! Then he wondered how this lizard survived for 10 years without moving a single step—since its foot was nailed! So he stopped his work and observed the lizard: What has it been doing? What and how has it been eating? Later, he didn't know from where another lizard appeared, with food in its mouth. Ah! He was astonished and touched deeply. The free lizard had been feeding it for the past 10 years.

    Such love, a beautiful love! Such love happened with this tiny creature… What can love do? It can do wonders! Just think about it: one lizard had been feeding the other for 10 long years, without giving up hope on its partner. If a small creature like a lizard can love like this, just imagine how we can love if we try.

    The evidence for harmony may not be obvious in some families. But it seems that four out of five young people now get on with their parents, which is the opposite of the popularly held image of unhappy teenagers locked in their room after endless family quarrels.

    An important new study into teenage attitudes surprisingly shows that their family life is more harmonious than it has ever been in the past." We were surprised by just how positive today's young people seen to be about their families," said one member of the research team. "They're expected to be rebellious(叛逆的) and selfish but actually they have other things on their minds; they want a car and material goods, and they worry about whether school is serving them well. There's more negotiation and discussion between parents and children, and children expect to take part in the family decision-making process. They don't want to rock the boat."

    So it seems that this generation of parents is much more likely than parents of 30 years ago to treat their children as friends. "My parents are happy to discuss things with me and willing to listen to me," says 17-years-old Daniel Lazall. "I always tell them when I'm going out clubbing. As long as they know what I'm doing, they're fine with it." Susan Crome, who is now 21, agrees." Looking back on the last 10 years, there was a lot of what you could call negotiation. For example, as long as I'd done all my homework, I could go out on a Saturday night. But I think my grandparents were a lot stricter with my parents than that."

    Maybe this positive view of family life should not be unexpected. It is possible that the idea of teenagers' rebellion is not rooted in real facts. A researcher comments, "Our surprise that teenagers say they get along well with their parents comes because of a brief period in our social history when teenagers were regarded as different beings. But that idea of rebelling and breaking away from their parents really only happened during that one time in the 1960s when everyone rebelled. The normal situation throughout history has been a smooth change from helping out with the family business to taking it over."

    They hide in trees, hang from helicopters, even follow people down on motorcycles—all so that they can snap a shot of a celebrity. They are paparazzi—photographers who make a living by taking pictures of the rich and famous.

    This September, California, a state with plenty of celebrities, passed a law aimed at taking action against paparazzi. The law forbids photographers from entering private property to take pictures, from using high-tech devices to take pictures of people on private property, and from "persistently following in order to take a picture." Violators can be fined or spend time in prison. The United State Congress is considering passing a similar law.

    Supporters of the California law say it will protect the privacy of celebrities, whom paparazzi have been bothering for years. Opponents (反对者) say the law restricts photojournalists from doing their job.

    Most celebrities seem to like having their pictures taken when they are in public at award shows or other events. After all, it's free publicity. But when they're not in public, they say, photographers should leave them alone. Yet paparazzi have been known to secretly look in windows and worse. Actor Michael J. Fox said that paparazzi have even "tried to pretend to be medical personnel at the hospital where my wife was giving birth to our son."

    Celebrities have as much right to their privacy as anyone else, supporters of the law state. Supporters further argue that the California law is a fair way to keep the press at bay, because the law still allows photographers to do their job. It only punishes them, supporters say, when they violate celebrities' privacy.

    Opponents of the law say it violates the First Amendment to the United States Constitution (美国宪法第一修正案), which guarantees that no laws will be made to limit "the freedom of speech, or of the press." Although some people might not consider paparazzi a part of the legal press, the California law does not single out paparazzi. It applies to photographers working for any publication.

    Opponents of the law are also concerned about its wording. "Does 'persistently' mean following someone for six minutes, six seconds, or six days?" asked lawyer Douglas Mirell. The wording of the law is too vague, critics complain, and could be used to punish almost any news photographer.

    The United States needs a free press to keep the public informed about important news, paparazzi law opponents say. Limiting the press in any way, they argue, limits the freedom of all.