When asked to point out one or two things that are most important to themselves, many put friends ahead of homes, jobs, clothes and cars.

    A true friendship carries a long history of experience that determines who we are and keeps us connected. It is a treasure we should protect. Unfortunately, the better friends you are, the more probably you'll have disagreements. And the result can be what you don't want—an end to the relationship.

    The good news is that most troubled friendships can be mended. First, don't let your pride get in your way. Most of us can forgive each other when differences are brought out in the open. Second, apologize when you're wrong — even if you've been wronged. Over the course of a friendship, even the best people make mistakes. Sometimes, it may be best if the wronged person takes the lead and apologizes. When you apologize, give your friend a chance to admit(承认) that he has been wrong. Third, see things from your friend's point of view. And finally, accept that friendships change as our needs and lifestyle change. Making friends can sometimes seem easy. The hard part is keeping the connections strong during the natural ups and downs that have an effect on all relationships. My suggestion: consider friendship as an honor and a gift, and worth the effort to treasure and nurture(培养).

    Most painters discover a style of painting that is fit for them and stick to that, especially if people admire their pictures. But Picasso, the great Spanish painter, was like a man who had not yet found his own particular style of painting. He kept on struggling to find the perfect expression till his death in 1973.

    Some of Picasso's paintings are rich, soft colored and beautiful. Others are ugly and cruel and strange. But such paintings allow us to imagine things for ourselves. They force us to say to ourselves, “What does he see that makes him paint like that?” And we begin to look under the surface of the things we see.

    Picasso painted thousands of pictures in different styles. Sometimes he painted the natural look of things. Sometimes he seemed to break them apart and throw the pieces in our faces. He showed us what the mind knows as well as what the eyes see. At the age of 90,he remained as curious about the world as he had been when he was young. That is why people have called him “the youngest painter in the world.”

    Two of the saddest words in the English language are “if only". I live my life with the goal of never having to say those words, because they convey regret, lost opportunities, mistakes, and disappointment.

    My father is famous in our family for saying, “Take the extra minute to do it right." I always try to live by the “extra minute" rule. When my children were young and likely to cause accidents, I always thought about what I could do to avoid an “if only" moment, whether it was something minor like moving a cup full of hot coffee away from the edge of a counter, or something that required a little more work such as taping padding (衬垫) onto the sharp corners of a glass coffee table.

    I don't only avoid those “if only" moments when it comes to safety. It's equally important to avoid “if only" in our personal relationships. We all know people who lost a loved one and regretted that they had foregone an opportunity to say “I love you" or “I forgive you." When my father announced he was going to the eye doctor across from my office on Good Friday, I told him that it was a holiday for my company and I wouldn't be here. But then I thought about the fact that he's 84 years old and I realized that I shouldn't give up an opportunity to see him. I called him and told him I had decided to go to work on my day off after all.

    I know there will still be occasions when I have to say “if only" about something, but my life is definitely better because of my policy of doing everything possible to avoid that eventuality. And even though it takes an extra minute to do something right, or it occasionally takes an hour or two in my busy schedule to make a personal connection, I know that I'm doing the right thing. I'm buying myself peace of mind and that's the best kind of insurance for my emotional well-being.

    Let us begin by saying what causes our dreams. Our dreams do not come from another world. They are not messages from some outside source. They are not a look into the future, either.

    All our dreams have something to do with our feelings, fears, longings, wishes, needs and memories. If a person is hungry, or tired, or cold, his dreams may include a feeling of this kind. If the covers on your body, such as a quilt or a blanket, have slipped off your bed, you may dream that you are sleeping on ice or in snow. The material for the dream you will have tonight is likely to come from the experience you have today.

    So the subject of your dream usually comes from something that has effect on you while you are sleeping（feeling of cold, a noise, a discomfort, etc. ）and it may also use your past experiences and the wishes and the interests you have now. This is why children are likely to dream of fairies, older children of school examinations, hungry people of food, homesick soldiers of their families and prisoners of freedom.

    To show you how this is happening while you are asleep and how your needs and wishes can all be joined together in a dream, here is the story of the experiment. A man was asleep and the back of his hand was rubbed with a piece of absorbed cotton. He would dream he was in hospital and his charming girlfriend was visiting him, sitting on the bed and feeling his hand gently!

    There are some scientists who have made a special study of why we dream, what we dream and what those dreams mean. Their explanation of dreams, though a bit reasonable, is not accepted by everyone but it offers an interesting approach to the problem. They believe that dreams are mostly expressions of wishes that did not come true. In other words dreaming is a way of having your wishes carried out.

    A few years back I worked in a university building that also housed a department full of psychologists, all of whom seemed to see us as perfect guinea pigs(豚鼠) for their latest theories. If an eager graduate student showed up in my office bearing desserts and asked me to pick one, I'd cast a careful glance and ask "Why?" before grabbing the apple pie.

    So one day, when someone from the Psychology Department posted instructions in the bathroom persuading all of us to "Think about five things for which you're grateful every day for a week!" my response was frankly doubtful. I did the math. Five things a day for seven days is a lot of brainpower to expend without so much as the promise of an apple pie.

    I wandered into the office of Heidi Zetzer, the director of our school's Psychological Services Clinic. "What's with the gratitude thing?" I asked. You don't ask an academic question－even a simple one unless you're prepared for a long answer. Heidi came alive, and I sat down. That's when I first heard the term "positive psychology". The gratitude thing, as I had called it, was but one small and simple element of the practice. "Kind of like training the brain to focus on joy," my friend Heidi explained. "It's only a week," she urged. "Try it." I did. And guess what? It worked.

    Every day for a week, I found five distinct things for which I was thankful. They had to be different every day. I couldn't get away with just being grateful for my wonderful husband. But I could, suggested Collie Conoley, another positive psychologist, express my gratitude for specific aspects of a certain person each day. He's a great cook. He always puts our family first.

    Life will never be perfect. I still see new stories that annoy me. The traffic in my city is maddening. I wish I could speed up my recovery. But with just one simple exercise, I'm rediscovering the peace of that old saying: accepting the things I can't change, working without complaint to change what I can, and being wise enough to know the difference.

    And all it took was a little gratitude.

A kind of blue dye (颜料) called folium had been widely used to paint pictures on the pages of manuscripts (手稿) created in the Middle Ages. But long ago, this watercolor fell out of use.

"Manuscripts are an important part of the cultural works of art in the Middle Ages," said scientist Maria in an email to CNN. "Color is a basic feature of these manuscripts. To let ancient manuscripts. keep a good condition for future generations, we sometimes need to repaint their inside pictures through the ancient dye — like folium — that was once used in these manuscripts. But everyone who knew how to prepare folium had died long ago. So 'I led a team to study this dye."

Her team turned to books from the 1400s and found one that described the plant that was its source. It is a tiny plant with silvery-green leaves. Days later, the scientists reached a village in south Portugal, where nobody knew this little plant. However, after carefully going through a plenty of different plants growing there, the scientists finally raked out the plant they wanted and brought some back to their laboratory.

Back in the lab, the scientists produced the dye with the help of an ancient text on colors. The text has clearly described the ways to make it. "It's cool to have done that work of looking in the historical records and traveling back in time," says Casadio, who was not part of this study. It recreates an ancient process. By making the dye, the scientists could study its chemistry without experimenting on priceless delicate (易损的)  works of art, she points out.

Now, the researchers don't know the dye's stability(稳定性)and its ability against the environment that may wear and break it down over time. "To know such information is necessary if we desire to make these colors last long enough," Maria said. "So our study will continue."