Do you believe that things are connected for no scientific reason at all? For example, do you avoid saying the word “four” to avoid bad luck? If so, you have a superstition (迷信). And you're not alone — all kinds of people have them.

    For example, Portugal's soccer superstar Cristiano Ronaldo always steps onto the pitch (球场) with his right foot first, according to The Telegraph. And sports players are not alone in having superstitions. A visitor once asked the Nobel Prize winning scientist Niels Bohr whether he really believed that the horseshoe he'd hung at his country home was lucky. “Of course not,” the Danish physicist said. “But I understand it's lucky whether you believe in it or not.”

    One recent study found that even scientists at MIT and other top US schools tended to look for a meaning in natural events, similar to the connection between stepping on the pitch and playing soccer well, according to The Atlantic. When the researchers gave the scientists little time to answer questions, they were twice as likely to agree with statements such as “Trees produce oxygen so that animals can breathe” as they were when they had more time to think about their reply.

    It seems that fear can make people think differently in this way, too. In a British study, students imagined meeting a “witch” who said she would cast (施魔法) an evil spell(符咒) on them. About half said a scientist should not be worried about the spell. Yet each of them said that, personally, they wouldn't let the witch do it to them.

    So why are so many of us superstitious? Well, it seems to be our way of dealing with the unknown. “Many people quite simply just want to believe,” Brian Cronk, a professor of psychology at Missouri Western State University, said in a 2008 interview. “The human brain is always trying to work out why things happen, and when the reason is not clear, we tend to make up some pretty bizarre (古怪的) explanations.”

    And these explanations aren't completely unhelpful. In fact, superstitions can sometimes work and bring real luck, according to psychologists at the University of Cologne in Germany in the May 2010 issue of the journal Psychological Science. They found that believing in something can improve performance on a task like an exam.

    So, what about you? What superstitions do you follow to keep you safe and successful?

    A poor farmer had a friend who was famous for the wonderful apples he grew. One day， his friend gave him a young apple tree and told him to take it home and 1 it.

    Seeing the gift， the farmer was very happy， and he thought he would also have a lot of wonderful apples， but when he got home， he felt 2 . He did not know where to plant it. He thought over and over and considered every place he could think of. 3 ， he decided to plant the tree in his woods. There were many high trees with thick leaves in the woods. With those trees around ，no one else could see the young apple tree. He even felt proud of himself for finding so secret a place for the apple tree. Every day he went to take care of the tree， watering it. To his surprise and 4， the apple tree didn't grow as well as he expected.  It died without sunlight and good soil.

    Later the friend asked the farmer why he had planted the tree in such a 5place. "What's the difference?" the farmer said angrily. "If I had planted the tree near the6， passers-by(行人) would have stolen the fruit. If I had planted the tree in one of my fields， my neighbors would have come at night and 7 some of the apples! If I had planted it near my house， my own children would have taken the fruits. No matter where I plant the tree， I can't have8 to enjoy the apples： So there is no difference where I planted it."

    "Yes，" said the friend. "But sooner or later someone could have enjoyed the fruit. Now you not only have robbed(抢夺) everyone of the fruit， but also have 9 a good apple tree! You don't know the true meaning of 'share'!"

    We should learn to 10in our life. The more you want to own something all by yourself， the less you get at last.

已知：若 ≈1.910， ≈6.042，则 ≈____．