When other nine-year-old kids were playing games, she was working at a petrol station. When other teens were studying or going out, she fought to find a place to sleep on the street. But she beat these terrible setbacks（挫折） to win a highly competitive scholarship and gain entry （录入）into Harvard University. And her amazing story has inspired a movie, “Homeless to Harvard: The Liz Murray Story”.

    Liz Murray, a 22-year-old American girl, has been writing a real-life story of willpower and determination. Liz grew up with two drug-addicted parents. There was never enough food or warm clothes in the house. Liz was the only member of the family who had a job. Her mother had AIDS and died when Liz was just l5 years old. The effect of that loss became a turning point in her life. Connecting the environment in which she had grown up with how her mother had died. She decided to do something about it.

    Liz went back to school. She threw herself into her studies, never telling her teachers that she was homeless. At night, she lived on the streets. “What drove me to live on had something to do with understanding, and by understanding that there was a whole other way of being. I had only experienced a small part of the society,” she wrote in her book Breaking Night.

    She admitted that she used envy （妒忌）to drive herself on. She used the benefits that come easily to others, such as a safe living environment, to encourage herself that “next to nothing could hold me down”. She finished high school in just two years and won a full scholarship to study at Harvard University. But Liz decided to leave her top university a couple of months earlier this year in order to take care of her father, who has also developed AIDS. “I love my parents so much. They are drug addicts. But I never forget that they love me all the time. ”

    Liz wants moviegoers（常看电影的人） to come away with the idea that changing your life is “as simple as making a decision”.

    A little boy discovered what looked like a map to an unknown place. He soon realized it was the beginning of an exciting treasure hunt.

    He found two pieces of paper along with the mysterious map. One was written with the instructions, “FIND THE WORDS.” The other piece of paper had several strange symbols scattered all over it.

    Dad, fortunately, was there to help his son figure out the mystery. He folded up the paper with the symbols on it, and together they formed a message, which had another set of instructions, “UNDER STEPS.” The smart little boy knew exactly what to do so he went to look under the steps of his house. Without too much effort, he found a box below the staircase.

    It didn't take him long to figure out what to do next: open it up! Inside the box were some very interesting objects, including another piece of a treasure map and two broken pieces of paper. These were the most interesting finds because they contained what appeared to be a collection of letters on them. Finally, they knew where the treasure was from the letters: IN THE BUSH UNDER YOUR YARD.

    After searching all over the yard, following several clues and wondering where everything would lead, the pair finally found what they had been looking for. And it was exactly what you would want after such an adventure: a treasure box!

    The pair pulled it out of the ground and cleaned away all the dirt. The dad put the box in front of his son, and the little boy couldn't contain his excitement. So he opened it up and finally found out what was inside.

    Inside was more treasure than any little boy could ever want. There were hundreds of coins and all sorts of pirate treasure, including what looks like a pearl necklace and some silver dishes.

    Like people, plants experience stress. And also, like people, the response to that stress can determine success.

    Bad environmental conditions, such as drought, flood, heat and other stresses, affect yields (产量) more than crop pests and diseases. We are trying to find a way to equip plants with the ability to tolerate environmental stress and maintain high yields, said Stephen Howell, a professor of genetics and cell biology.

    Plant cells produce proteins (蛋白质) and ship them to different parts of the cell. Under normal conditions, these proteins are folded into their normal, healthy structures as they are produced. When a plant is under stress, its cells produce poorly folded or unfolded proteins. Then a built-in system senses this and “sets off an alarm in the cell,” said Howell.

    In response to the alarm, another protein (IRE1) starts working and creates a different process which activates (激活) the stress response genes whose products bring about defensive measures that help the plant survive.

    “As it turns out, responses that are activated under stress conditions actually inhibit the growth of plants,” said Howell. “This allows them to preserve their energy to survive the stress conditions.”

    For plants in the wild, this response is a help for survival, he said. In production of agriculture crops, however, this response reduces yields.

    “You don't want crop plants to stop growing,” Howell said. “You want them to continue to grow and produce even though they are under stress.”

    With the new understanding of this stress response, the next step may be to silence the alarm system, said Howell. “What may be important is to disable some of these stress responses. That may make the plant more productive under stress conditions.”

    Have you ever pressed the pedestrian button at a crosswalk and wondered if it really worked? They're called “placebo(安慰剂）buttons” 一buttons that mechanically sound and can be pushed，but provide no functionality.

In New York City, only about 100 of the 1, 000 crosswalk buttons actually function. Crosswalk signals were generally installed before traffic jam had reached today's levels.

    But while their function was taken over by more advanced systems—such as automated lights or traffic sensors — the physical buttons were often kept, rather than being replaced at further expense. Other cities，such as Boston， Dallas and Seattle， have gone through a similar process, leaving them with their own placebo pedestrian buttons. In London, which has 6, 000 traffic signals， pressing the pedestrian button results in a reliable “Wait” light. But that doesn't necessarily mean that the “green man”— or “pedestrian stage” in traffic signal design profession — will appear any sooner.

    “We do have some crossings where the green light comes on automatically, but we still ask people to press the button because that enables accessible features,'' said Glynn Barton, director of network management at Transport for London.

    These features, such as blind tracks and hearable traffic signals, help people with visual disorder cross the road and only function when the button is pressed. As for the lights, a growing number of them are now combined and become a part of an electronic system that detects traffic and adjusts time frequency accordingly (giving priority to buses if they're running late, for example), which means that pressing the button has no effect.

    According to Langer, a Harvard psychologist, placebo buttons give us the illusion (错觉)of control — and something to do in situations where the alternative would be doing nothing. In the case of pedestrian crossings, they may even make us safer by forcing us to pay attention to our surroundings. “They serve a psychological purpose at the very least,” she added.

    It started during a yoga class. She felt a strange pull on her neck, a feeling completely foreign to her. Her friend suggested she rush to the emergency room. It turned out that she was having a heart attack.

    She didn't share similar symptoms with someone who was likely to have a heart attack. She exercised, watched her plate and did not smoke. But on reviewing her medical history, I found that her cholesterol (胆固醇) level was sky-high. She had been prescribed a cholesterol-lowering statin (他汀) medication, but she never picked up the prescription because of the scary things she had read about statins on the Internet. She was the victim of fake medical news.

    While misinformation has been the object of great attention in politics, medical misinformation might lead to an increase in deaths. As is true with fake news in general, medical lies tend to spread further than truths on the Internet—and they have very real bad consequences.

    False medical information can also lead to patients experiencing greater side effects through the "nocebo effect (反安慰剂效应) ". Sometimes patients benefit from an intervention (干预) simply because they believe they will—that's the placebo effect (安慰剂效应). The nocebo effect is the opposite. Patients can experience harmful effects because they anticipate them. This is very true of statins. In blinded trials, patients who get statins are no more likely to report feeling muscle aches than patients who get a placebo. Yet, in clinical practice, according to one study, almost a fifth of patients taking statins report side effects, leading many to discontinue the drugs.

    What else is on the fake news hit list? As always, vaccines (疫苗) . False concerns that the vaccine may cause side effects have greatly reduced coverage rates.

    Cancer is another big target for pushers of medical misinformation—many of whom refuse alternative therapies. "Though most people think cancer tumors are bad, they're actually the way your body attempts to contain the harmful cells," one fake news story reads. It warns that prescription medications lead to the uncontrolled cell mutations (变异) .

    Silicon Valley needs to face this problem. I am not a free-speech lawyer, but when human health is at risk, perhaps search engines, social media platforms and websites should be held responsible for promoting or hosting fake information. Meanwhile, journalists should do a better job of spreading accurate information.

    By now you've probably heard about the "you're not special" speech, when English teacher David McCullough told graduating seniors at Wellesley High School: "Do not get the idea you're anything special, because you're not." Mothers and fathers present at the ceremony 一 and a whole lot of other parents across the Internet — took issue with McCullough's ego-puncturing (伤自尊的) words. But lost in the uproar (喧嚣)was something we really should be taking to heart: our young people actually have no idea whether they're particularly talented or accomplished or not. In our eagerness to elevate their self-esteem, we forgot to teach them how to realistically assess their own abilities, a crucial requirement for getting better at anything from math to music to sports. In fact, it's not just privileged high-school students: we all tend to view ourselves as above average.

    Such inflated self-judgments have been found in study after study and it's often exactly when we're least competent at a given task that we rate our performance most generously, in a 2006 study published in the journal Medical Education, for example, medical students who scored the lowest on an essay test were the most charitable in their self evaluations, while high-scoring students judged themselves much more strictly. Poor students, the authors note, "lack insight" into their own inadequacy. Why should this be? Another study, led by Cornell University psychologist David Dunning, offers an enlightening explanation. People who are incompetent, he writes with coauthor Justin Kruger, suffer from a “dual burden": they're not good at what they do, and their very clumsiness prevents them from recognizing how bad they are.

    In Dunning and Kruger's study, subjects scoring at the bottom on tests of logic, grammar and humor -extremely overestimated'' their talents. Although their test scores put them in the 12th percentile (百分位数) they guessed they were in the 62nd. What these individuals lacked (in addition 9 clear logic, proper grammar and a sense of humor) was "meta cognitive skill" the capacity to monitor how well they're performing. In the absence of that capacity, the subjects arrived at an overly hopeful view of their own abilities. There's a paradox here, the authors note: The skills that lead to competence in a particular domain are often the very same skills necessary to evaluate competence in that field? In other words, to get better at judging how well we're doing at an activity, we have to get better at the activity itself.

    There are a couple of ways out of this double bind. First, we can learn to make honest comparisons with others. Train yourself to recognize excellence, even when you yourself don't possess it, and compare what you can do against what truly excellent individuals are able to accomplish. Second, seek out feedback that is frequent, accurate and specific. Find a critic who will tell you not only how poorly you're doing, but just what it is that you're doing wrong. As Dunning and Kruger note, success indicates to us that everything went right, but failure is more ambiguous: any number of things could have gone wrong. Use this external feedback to figure out exactly where and when you screwed up.

    If we adopt these strategies — and most importantly, teach them to our children — they won't need parents, or a commencement (毕业典礼)speaker, to tell them that they're special. They'll already know that they are, or have a plan to get that way.