The advice offered from any other 82-year-olds might have made young people yawn and roll their eyes. But when former South African president Nelson Mandela advised two dozen local youth leaders in Los Angeles to take education seriously, his audience was listening.

    The famed old man said to the young people that if they expected to improve the lives of others in the future, they must work at improving their own lives now. "Education is one of the most important weapons you have,” Mandela advised. “It will place you in a far better position to serve yourself and your community.”

“The point is, he was young once and rebellious(叛逆的)once and he kept his dream alive, just as you each have dreams,” explained South Africa's ambassador to the United States, Sheila Sisulu, as she introduced Mandela to the young crowd.

    Asked for specific advice about changing society by 21-year-old Ahmed Younis, Mandela suggested that somehow helping arouse more American interest in foreign affairs might be a start.

There is an impression that Americans, in general, have not followed international developments properly, Mandela said. “I'm not making that statement myself, but there are serious political analysts who say Americans are not well informed as to what has happened in the world.”

22-year-old Omari Trice said Mandela left him full of enthusiasm. “ He's a person who set the tone for an entire nation, said Trice. “You come away feeling you need to be a superman in order to get things done.”

    Since English biologist Charles Darwin published On the Origin of Species in 1859, scientists have vastly improved their knowledge of natural history. However, a lot of information is still of the speculation, and scientists can still only make educated guesses at certain things.

    One subject that they guess about is why some 400 million years ago, animals in the sea developed limbs (肢) that allowed them to move onto and live on land.

    Recently, an idea that occurred to the US paleontologist (古生物学家) Alfred Romer a century ago became a hot topic once again.

    Romer thought that tidal (潮汐的) pools might have led to fish gaining limbs. Sea animals would have been forced into these pools by strong tides. Then, they would have been made either to adapt to their new environment close to land or die. The fittest among them grew to accomplish the transition (过渡) from sea to land.

    Romer called these earliest four-footed animals “tetrapods”. Science has always thought that this was a credible theory, but only recently has there been strong enough evidence to support it.

    Hannah Byrne is an oceanographer (海洋学家) at Uppsala University in Sweden. She announced at the 2018 Ocean Sciences Meeting in Oregon, US, that by using computer software, her team had managed to link Homer's theory to places where fossil deposits (沉积物) of the earliest tetrapods were found.

    According to the magazine Science, in 2014, Steven Balbus, a scientist at the University of Oxford in the UK, calculated that 400 million years ago, when the move from land to sea was achieved, tides were stronger than they are today. This is because the planet was 10 percent closer to the moon than it is now.

    The creatures stranded in the pools would have been under the pressure of “survival of the fittest”, explained Mattias Green, an ocean scientist at the UK's University of Bangor. As he told Science, “After a few days in these pools, you become food or you run out of food... the fish that had large limbs had an advantage because they could flip (翻转) themselves back in the water.”

    As is often the case, however, there are others who find the theory less convincing. Cambridge University's paleontologist Jennifer Clark, speaking to Nature magazine, seemed unconvinced. “It's only one of many ideas for the origin of land-based tetrapods, any or all of which may have been a part of the answer,” she said.

    Two years ago, something happened that changed the way I look at the world. On my birthday, my grandfather, walking home with his hands full of groceries, fell and hit his head on the sidewalk. Just as we were leaving to meet him for dinner, we got the call that he was in the hospital. At first, I thought nothing of it, but when I heard the whole story, I couldn't believe it. He hit his head so hard that he had a blood clot in his brain and it had to be operated on immediately. Everyone thought he would die.

    Although my grandfather survived emergency brain surgery, he had complications (后遗症). He could hardly talk and he couldn't walk. Shortly after, he was admitted to a nursing home. Today, he lives at home with my grandmother and is doing much better, but this isn't about him. It's about what I saw at that nursing home.

    I saw something that many people haven't seen, and some do often choose to ignore it, I saw more sadness in those days visiting the nursing home than I thought. In that one place were hundreds of old people who were alone and forgotten.

    So what as to be done with the situation of the old? This is not an easy question, but something must be done. Perhaps groups in the community could assign each member to one nursing home patient with whom they could keep in regular contact. Maybe a school could focus on a nursing home and send cards, pictures and letters to residents. If periodic visits were arranged, I'm sure that for some, if not many, those students would be the only visitors they had all month. These are just a few ideas; we all need to work together.

    I hope everyone to tour a local nursing home I further expect you to do something about it. You'll brighten someone's day, or maybe even his or her life.

    If 62 is the number in red on the top of your math test, for most of us, it's a total disaster. Your entire week is ruined, and 62 is what races through your head for the rest of the day. If 9 is the number of likes on that cute photo you posted the other day, many will feel rather disappointed.

    Our lives have become a constant system of ranks, assessments, and numbers. The days of passing judgment on others based on personality are gone, and now we judge based on how good a person's numbers are. We compare ourselves to the numbers of others, such as how low another person's weight is how high their paycheck. Self-worth is no longer based on quality of character, but quantity of numbers.

    In today's social media consumed society, it has never been easier for people to broadcast their numbers to the world. A simple click of a button can take you to a page where you can observe the number of friends or followers a person has. Teenagers have taken on this mentality that if you don't have a certain number of followers, then you aren't "cool". Many feel they are not important if very few people are witnessing their status updates. This state of mind is harmful and not at all accurate. Twitter and Facebook can let the world witness your updates, but they will never let anyone see who you really are. In the end, self-worth should be based on what you think of yourself, not what the world thinks of you.

    So next time you receive a failing grade or you lose a follower, remember that these things cannot and should not define (定义) you. You are not your numbers. You are a person-a3-D living and breathing person with ideas and creativity and love that the rigidity of numbers cannot represent. You are the things you love and the things you laugh at and the way you treat others.

    "Have a nice day!" may be a pleasant gesture or a meaningless expression. When my friend Maxie says "Have a nice day" with a smile, I know she sincerely cares about what happens to me. I feel loved and secure since another person cares about me and wishes me well.

    "Have a nice day. Next!" This version of expression is spoken by a salesgirl at the supermarket who is rushing me and my groceries out the door. The words come out in the same tone(腔调)with a fixed procedure. They are spoken at me, not to me. Obviously, the concern for my day and everyone else's is the management's attempt to increase the business.

    The expression is one of those behaviors that help people get along with each other. Sometimes it indicates the end of a meeting. As soon as you hear it, you know the meeting is at an end. Sometimes the expression serves us when we don't know what to say." Oh, you just had a tooth out? I'm terribly sorry, but have a nice day."

    The expression can be pleasant. If a stranger says "Have a nice day" to you, you may find it heart-warming because someone you don't know has tried to be nice to you.

    Although the use of the expression is an insincere, meaningless social custom at times, there is nothing wrong with the sentence except that it is a little uninteresting. The salesgirl, the waitress, the teacher, and all the countless others who speak it without thinking may not really care about my day. But in a strange and comfortable way, it's nice to know they care enough to pretend they care when they really don't care all that much. While the expression may not often be sincere, it is always spoken. The point is that people say it all the time when they like.

A Lesson Plan from Life Planning Education: A Youth Development Program

    Purpose: To learn about body language and how to use body language.

    Materials (材料): Cards; container

    Time: 25-35 minutes

    Planning Notes:

    ·Write the words below on cards:

    angry disappointed shy afraid sad happy nervous excited bored

    ·Place the cards in the container so volunteers can draw them out one at a time.

    Steps:

    First make sure that all volunteers know what body language means (expressing feelings through body movement and facial expressions). Go over the following instructions:

    ·I'll need at least 9 volunteers to play a game similar to charades (猜词游戏).

    ·The first volunteer will draw a card with a feeling written on it and act out the feeling without using words.

    ·The rest of the group will guess what feeling is being communicated. Once someone correctly guesses the feeling, the next person in line will draw a card and act out what is written on it, again without words.

    ·The game will continue until there are no more cards or until time is up.

    At last, end the activity using the discussion points below:

    ·Can you give examples of when someone's body language communicated a different message from what he/she actually skid?

    ·Sometimes one person is offended (冒犯) by another's body language. How can you work to keep that from happening? Answers may include: be honest and direct; match your nonverbal messages to your verbal ones; be aware of (清楚) cultural attitudes toward different kinds of body language.