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?”

    Passing through the Atlanta airport one morning, I caught one of those trains that take travelers from the main terminal to their boarding gates. Free, and impersonal, the trains run back and forth all day long. Not many people consider them fun, but on this Saturday I heard laughter. At the front of the first car – looking out the window at the track that lay ahead – were a man and his son.

    We had just stopped to let off passengers, and the doors were closing again. "Here we go! Hold on to me tight!" the father said. The boy, about five years old, made sounds of sheer delight.

    I know we're supposed to avoid making racial distinctions(种族歧视) these days, so I hope no one will mind if I mention that most people on the train were white, dressed for business trips or vacations.

    As I got off, I remembered something I'd wanted to buy in the terminal. I was early for my flight, so I decided to go back.

    I did – and just as I was about to reboard the train for my gate, I saw that the man and his son had returned too. I realized then that they hadn't been heading for a flight, but had just been riding the shuttle.

    "I want to ride some more!"

    "More?" the father said, mock-exasperated(嗔怪模仿) but clearly pleased. "You're not tired?"

    "This is fun!" his son said.

    "All right," the father replied, and when a door opened we all got on.

    There are parents who can afford to send their children to Europe or Disneyland, but the children turn out rotten. There are parents who live in million-dollar houses and give their children cars and swimming pools, yet something goes wrong. Rich and poor, black and white, so much goes wrong so often.

    "Where are all these people going, Daddy?" the son asked.

    "All over the world," came the reply. The other people in the airport were leaving for distant destinations or arriving at the ends of their journeys. The father and son, though, were just riding this shuttle together, making it exciting, sharing each other's company.

    Music is magic! Music speaks louder than words and it is a "language" that the whole world can understand. A piece of music can produce a response in the heart and mind. Like feeling an electrical current or receiving a personal radio signal, music has a spiritual effect on a person. Different kinds of music influence people in different ways.

    I have listened to music all my life. When I was twelve years old, the Beatles came to America and my whole world opened up. Maybe young people today cannot understand the influence of the Beatles when they exploded across America. Their influence changed the way we dressed, looked, acted and spoke, even our culture. The Beatles arrived in America from the UK just three months after the assassination(暗杀) of President John Kennedy, which had put America into a great depression. And the freshness and lively spirit of the Beatles was exactly what the country needed to refresh itself.

    Music links the heart of the hearer with that of the composer. This means that it mixes the spirit of the composer with your spirit when you listen to it. And the music can take your spirit out of your body and transport you into another world. Music has a great way of touching people. Music can make you laugh, cry or shout. It's also a great source of inspiration.

    Try this one day and notice what happens: make yourself a cup of tea, sit on your sofa and play one of your favorite songs. Close your eyes, and soon you'll find yourself creating vivid mental images matching the music that you are listening to.

    Beyoncé Knowles can do something that many humans struggle with: sing and dance at the same time. But, it turns out this great ability is not unique to humans. The superb lyrebird, already known to be a gifted singer, can perform coordinated(协调的)song­and­dance routines(一套舞蹈动作)that put most humans to shame.

    The superb lyrebird is one of only two lyrebird species living in Australia, the other named Albert's lyrebird. Male lyrebirds have tails in the shape of an ancient musical instrument when spread out. Like most animals with beautiful body parts, the males use their tails to attract females. Each one sets up a small mound(小丘)on the forest floor, where he walks around proudly and sings. He also shows his tail by holding it over his head.

    Lyrebirds are gifted mimics(模仿者), so their songs combine their own calls, the songs of other species, and sounds they have heard in the forest. That would be enough showing off for other animals, but male superb lyrebirds also dance.

    Anastasia Dalziell of the Australian National University in Canberra filmed 12 lyrebirds in the wild. She found that males only danced during four song types, and that each song type was accompanied by a specific move. “Lyrebirds match different dance styles to different types of songs, ”she says. For example, when the male sang a series of rapid notes he also stepped to the side and held his tail wide. Another song type was accompanied by jumping and moving up and down, with the tail held narrow.

    “Our results suggest that the coordination between song and dance—like movements we see in humans can occur in other animals,” says Dalziell. Female lyrebirds might prefer males that are better at coordinating song and dance, although there is no evidence of that yet.

    Americans with small families own a small car or a large one. If both parents are working, they usually have two cars. When the family is large, one of the cars is sold and they will buy a van (住房汽车).

    A small car can hold four persons and a large car can hold six persons but it is very crowded. A van hold seven persons easily, so a family with three children could ask their grandparents to go on a holiday travel. They could all travel together.

    Mr. Hagen and his wife had a third child last year. This made them sell their second car and buy a van. In the van, the sixth and seventh seat are used to put other things, for a family of five must carry many suitcases when they travel. When they arrive at their grandparents' home, the suitcases are removed from the two seats which can then carry the grandparents.

    Americans call vans motor homes. A motor home is always used for holidays. When a family are traveling to the mountains or to the seaside, they can live in their motor home for a few days or weeks. All the members of a big family can enjoy a happier life when they are traveling together. That is why motor homes have become very popular. In America there are many parks for motor homes.

    Prosocial behaviors are those intended to help other people. Behaviors that can be described as prosocial include feeling empathy(同感) and concern for others and behaving in ways to help or benefit other people.

    Prosocial behavior has long posed a challenge to social scientists seeking to understand why people engage in helping behaviors that are beneficial to others, but costly to the individual performing the action. Why would people do something that benefits someone else but offers no immediate benefit to the doer?

    Psychologists suggest that there are a number of reasons why people engage in prosocial behavior. In many cases, such behaviors are fostered during childhood and adolescence as adults encourage children to share, act kindly, and help others. Prosocial behaviors are often seen as being compelled by a number of factors including egoistic reasons (doing things to improve one's self­image), reciprocal benefits (doing something nice for someone so that they may one day return the favor), and more altruistic reasons (performing actions purely out of empathy for another individual).

    Characteristics of the situation can also have a powerful impact on whether or not people engage in prosocial actions. The bystander effect is one of the most notable examples of how the situation can impact helping behaviors. The bystander effect refers to the tendency for people to become less likely to assist a person in distress when there are a number of other people also present. For example, if you drop your purse and several items fall out on the ground, the likelihood that someone will stop and help you decreases if there are many other people present. This same sort of thing can happen in cases where someone is in serious danger, such as when someone is involved in a car accident. In some cases, witnesses might assume that since there are so many other present, someone else will have surely already called for help.

    Why do people help in some situations but not in others? Experts have discovered a number of different situational variables that contribute to (and sometimes interfere with) prosocial behaviors. First, the more people that are present decreases the amount of personal responsibility people feel in a situation. People also tend to look to others for how to respond in such situations, particularly if the event contains some level of ambiguity. Fear of being judged by other members of the group also plays a role. People sometimes fear leaping to assistance, only to discover that their help was unwanted or unwarranted. In order to avoid being judged by other bystanders, people simply take no action.

    Experts have suggested that some key things must happen in order for a person to take action.