If you want to learn anything at school, you need to listen to your teachers. Unfortunately, millions of kids can't hear what their teachers are saying. And it's not because these students are goofing off. Often, it's the room's fault. Building architecture and building design can create echo(回声)-filled classrooms that make hearing difficult.

    Children with hearing impairments（损伤）suffer most from noisy classrooms. They sometimes can't hear questions that other students ask in class. Compared with kids with healthy hearing, they have a harder time picking up new vocabulary words by hearing them in talking.

    Even kids with normal hearing have a harder time in the classroom when there's too much noise. Younger children in particular have trouble separating important sounds – like a teacher's voice – from background noise. Kids with learning disabilities and speech impediments（障碍）and kids for whom English is a second language also have a harder time learning in noisy situations.

    In recent years, scientists who study sound have been asking schools to reduce background noise, which may include loud air-conditioners and pipes. They're also targeting outdoor noises, such as highway traffic. Noise reduction is a big deal. Why? Because quieter classrooms might make you smarter by letting you hear your lessons better.

    “It's so obvious that we should have quiet rooms that allow for access to the lesson,” says Dan Ostergren, a hearing scientist. “Sometimes it surprises me that we spend so much time discussing this topic. I just want to go. Why is this hard for anyone to grasp?”

    Yesterday night, over a dinner with my elder brother's family, a topic of happiness came up. My wife, Marla, a psychologist, was sharing Csikszentmihalyi's concept of “flow” with us. Marla explained that according to the research on flow, people are happiest when they are absorbed in a task that is just challenging enough for them to experience a sense of mastery(熟练).

    A few moments later my brother, Yuri, offered the following opinion: “The first and only, necessary and sufficient factor for happiness is to stop associating happiness with pleasure. The two — happiness and pleasure — have nothing to do with each other.” This morning, with my cup of coffee, I searched through a pile of books on my bedside table and—at the bottom—found a book by Bertrand Russell, I started reading but didn't finish. In it, I found the following thought:

    “The human animal, like others, is adapted to a certain amount of struggle for life, and when by means of great wealth homo sapiens can gratify all his whims (突发奇想) without effort, the mere absence of effort from his life removes an essential ingredient of happiness.”

    The conversation came full circle: people are happiest when they are in a state of flow (Csikszentmihalyi's language )…which is the effortful devotion in a moment…which has nothing to do with pleasure.

    Indeed, as Yuri insisted : happiness–as–pleasure is a myth; the association between happiness and pleasure is nothing but a semantic(语义的) habit; psychologically, the two—happiness and pleasure—are arguably different; and breaking up this association between pleasure and happiness might, in fact, be a powerfully first step in pursuit of happiness.

    As I look back on that exchange, I recall that there was an effort, a struggle to find a common understanding about this seemingly difficult idea—a struggle that made me happy.

    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.

    Think plants are just boring green things that you use for food and decoration? Think again! Plants are able to do some pretty awesome things that you're probably totally unaware of.

    Researchers have discovered that plants have the ability to communicate with an underground network made up of fungus (真菌) , which serves the plants in many ways. Tomato plants use the fungus web to warn each other of their own unhealthy conditions. Trees connected through the fungus network could move nutrients (养分) to and from each other. It is believed that larger trees move nutrients to smaller ones to help them to survive.

    Not only that, but they can also damage unwelcome plants by spreading poisonous chemicals through the fungus. It sounds like the plant world had the Internet before we did.

    Some plants have a rather impressive line of defense against being eaten. When sensing they are being swallowed, they give off a chemical into the air that attracts the insect's natural enemy. The enemy attacks the bug, thus saving the plants. This is basically the plant kingdom version of getting your older brother to beat up that kid who steals your lunch money.

    You might be aware that humans and animals have an internal clock. But did you know that plants also have this clock? This means they can prepare for certain times of day just like we do. Is it because they can react to light at sunrise? In a study, scientists found that plants use the sugars they produce to keep time, which help to regulate the genes responsible for the plant's own internal clock. So, in a sense, wake up with petunias (矮牵牛) is just as valid as ―wake up with the chickens.

    Nature is full of surprises. So for those of you who didn't know the wonders of plants, now you do.

    It is a question people have been asking for ages—is there a way to turn back the aging process?

    For centuries, people have been looking for a "fountain of youth." The idea is that if you find a magical fountain, and drink from its waters, you will not become old. Spanish explorer Juan Ponce de León searched for waters with magical powers in the early 1500s. But what he found instead is the American State of Florida.

    Researchers in New York did not find a fountain of youth in fact, but they may have found a way to turn back the aging process. It appears the answer may be hidden right between your eyes, in an area called the hypothalamus (丘脑下部).The hypothalamus is part of your brain. It controls important activities within the body, including growth, reproduction and the way we process food.

    Researchers at New York's Albert Einstein College of Medicine found that hypothalamus stem cells also influence how fast aging takes place in the body. What are stem cells? They are simple cells that can develop into specialized cells, like blood or skin cells. Stem cells can also repair damaged parts in the body.

    Professor Dongsheng Cai was the lead researcher in a study on aging in mice. Cai explains in the Journal Nature what they found. "Aging speed can be controlled by a particular place in the body, which is the hypothalamus. And it can be controlled by a particular type of cells, which are hypothalamus stem cells. I think these findings are quite interesting."

    He adds that when the hypothalamus starts aging, so does the body. "So when hypothalamus function is decreasing, particularly the loss of hypothalamus stem cells, this protection against the aging development is lost. It finally leads to aging."

    Using this information, the researchers began trying to activate (激活) the hypothalamus in mice. They did this by putting stem cells from younger mice into middle-aged animals. Later, the researchers examined mice and tested for changes in behavior. They also looked for changes in the strength of the animals' muscles and the way they worked. The researchers say the results show that the treatment slowed aging in the animals.

    Cai says when hypothalamus stem cells, which were derived from young mice was put into middle-aged mice, the mice aged slowly and they also have increased the length of their lives.

    But these results were just from studying mice in a lab. If the mice can live longer, does that mean people could have longer lives? The next step is to see if the anti-aging effects also work in human beings.

Guilty Pleasures?

You might have heard of the expression ‘a guilty pleasure'—maybe it's the chocolate bar you buy on the way home from work, or the new clothes that you don't really need. It comes from the idea that when we treat ourselves, it can sometimes leave us feeling guilty. Perhaps we don't feel we deserved it, or we don't think it was a responsible way to spend our money. But should we feel like this? {#blank#}1{#/blank#}.

Perhaps not. Psychologists have suggested that buying things for yourself can make you feel better as it provides an opportunity to take control of your situation. {#blank#}2{#/blank#} It may be that as well as lifting your mood, when you buy a treat, you might just be looking after yourself.

Of course, there are also examples of people turning to destructive behaviour when faced with stressful circumstances. People might spend money that they don't have at all or turn to some dangerous addictions. {#blank#}3{#/blank#} Self-indulgence can be reckless and have negative consequences, while self-nurturing is taking responsible decisions to satisfy our needs and take care of ourselves in ways that don't have a significant impact.

{#blank#}4{#/blank#} Many universities publish guides with advice for coping with exam stress. It's essential to reflect the difference between self-indulgence and self-nurture. {#blank#}5{#/blank#} They also suggest doing things that you enjoy much and are good at so that you can feel accomplishment and to avoid things that may make you feel worse afterwards.

So perhaps, as long as we make responsible decisions, we shouldn't feel guilty about our guilty pleasures.

A. Do we need to have a guilty or clear conscience?

B. Do we really have to feel guilty about treating ourselves?

C. One stress that people may need to deal with is exam stress.

D. Psychologists recommend rewarding yourself for your efforts.

E. So we should keep a balance between self-indulgence and self-nurturing.

F. It can give you social contact and a confidence boost by changing your image.

G. Psychologist Leon Seltzer considers the difference between self-indulgence and self-nurturing.