Andy never wanted to go to bed on time. His parents had explained to him how important it was to go to bed early and get a good rest. But Andy paid no attention to them, and they didn't know what to do until one weekend when they were visiting Andy's grandparents.

    Grandpa Peter heard all about it and said, "This sounds like a job for Tubby." So Andy's parents loaded the cat onto the car and returned home.

That night, at bedtime, the same problem happened. Andy didn't want to go to bed, and even though his parents waited a while to see if Tubby would solve the problem, nothing happened.

    Hours later, Andy finally decided to go to bed. But what a surprise when he entered his bedroom! Tubby was in his bed, totally sprawling out, pot-belly in the air, and snoring like an express train.

    Andy tried to move the cat, but there was no way of moving him an inch. That night he hardly slept, lying on one tiny corner of his bed.

    The next day the same thing happened, even though Andy was much more tired from not having slept well. When the third day arrived, he had understood that if he wanted to sleep in his bed, he would have to get into it before Tubby did. That night, when his parents only started to mention the topic of bedtime, Andy rushed upstairs and dived into bed. His parents could not believe it. They knew nothing about Tubby in the bed, nor did they understand why Andy went to bed on time without complaint. They were so happy about this that they stayed up quite late, celebrating.

    Big Brothers Big Sisters is based on the simplicity and power of friendship．It is a program which provides friendship and fun by matching vulnerable young people (ages 7-17) with a volunteer adult who can be both a role model and a supportive friend.

    Volunteer tutors come from all walks of life—married, single, with or without children. Big Brothers and Big Sisters are not replacement parents or social workers. They are tutors: someone to trust, to have fun with, to talk and go to when needed.

    A Big Sister and Little Sister will generally spend between one and four hours together three or four times each month for at least twelve months. They enjoy simple activities such as a picnic at a park, cooking, playing sport or going to a football match. These activities improve the friendship and help the young person develop positive self-respect, confidence and life direction.

    Big Brothers Big Sisters organizations exist throughout the world. It is the largest and most well-known provider of tutor services internationally and has been operating for 25 years.

    Emily and Sarah have been matched since 2008. Emily is a 10-year-old girl who has experienced some difficulties being accepted by her schoolmates at school. “ I was pretty sure there was something wrong with me.”

    Emily's mum came across Big Brothers Big Sisters and thought it would be of benefit to Emily by “providing different feedback (反馈) about herself other than just relying on schoolmates to measure her self-worth.

    Sarah wanted to get involved in a volunteer program. “I googled it and found out how to be a part of it. I thought it would be fun for me to get involved in making time to do something because sometimes it is all work and no play.”

    Big Brothers Big Sisters has been of great benefit and enjoyment to both Emily and Sarah. They love and look forward to their time together and the partnership has certainly helped Emily be more comfortable in being the wonderful, happy and unique girl she is!

    As the world around them is changing, teenagers continue to need guidance and support from both parents. Studies show that teens who have an active relationship with their fathers are less likely(可能的)to involve themselves in dangerous behaviors and more likely to succeed in school and develop higher self-worth, because their fathers go beyond social expectations to devote attention to them.

    Peer(同龄人)pressure has always been a big part of the teens' experience. Even the best father can't completely protect their kids from the growing influence of their peer group. However, studies show that teenagers whose fathers focus on their lives are more likely to resist (抵抗)the more bad effects of peer pressure, taking drugs, for example.

    Teens may not like to admit it, but they are watching their parents closely and often follow their example. An interesting finding explains just how important parents are, especially Dad. Swiss researchers discovered that if Dad attends church, even though Mom doesn't, 44 percent of the kids are still more likely to keep going to church as adults. But if Mom goes regularly and Dad never shows up, only 2 percent of the kids continue to attend.

    Teenagers face a lot of difficult choices, especially in their later teens. Fathers don't get to make those choices for them, but they can be influenced. For example, teenagers can learn a lot from their parents' concern on what to do when they finish high school. Should they go directly to college and, if so, where? Should they consider going to trade schools, joining the army or looking for a job? A father's guidance brings a long-term perspective that teens often lack to these important decisions.

    Street art is a very popular form of art that is spreading quickly all over the world. You can find it on building, sidewalks, street sings and trash cans from Tokyo to Paris, and from Moscow to Cape Town. Street art has become a global culture and even art museums and galleries are collecting the works of street artists. Even advertising companies also use street art in their ads due to its popularity.

    Street art started out very secretly because it's illegal to paint on public and private property without permission. People often have different opinions about street art. Some people think it is a crime with others think it's a new form of culture.

    Art experts claim that the movement began in New York in the 1960s. Young adults sprayed words and images on walls and trains. This colorful and energetic style of writing became known as graffiti(涂鸦). Graffiti art showed that young people wanted to rebel against society. They didn't want to accept rules, and they travelled around cities to create paintings that everyone could see. In many cases, they had trouble with the police and the local government.

    Many street corners in Paris show the works of Space Invader. A French artist uses small pieces of glass to make images of space creatures. He has been doing this for some years and the police have arrested him a few times. On his website, you can see many other places where he has created this form of art.

    Street artists do their work for some reasons. Some of them do not like the artists who make so much money in galleries and museums. They choose street art because it is closer to common people. Some artists try to express their political opinion in their works. They often want to protest against big firms and corporations. Others like to do things that are forbidden and hope they don't get caught.

    In today's world, the Internet has a big influence on street art. Artists can show their pictures to people all over the world. Many city residents, however, say that seeing a picture on the Internet is never as good as seeing it alive. The street art movement lives with the energy and life of a big city. There it will continue to change and grow.

    According to new research from the University of Cambridge in England, sheep are able to recognize human faces from photographs.

    The farm animals, who are social and have large brains, were previously known to be able to recognize one another, as well as familiar humans. However, their ability to recognize human faces from photos alone is novel.

    The recent study, the results of which were published in the journal Royal Society showed that the woolly creatures could be trained to recognize still images of human faces, including those of former President Barack Obama and actress Emma Watson.

    Initially, the sheep were trained to approach certain images by being given food rewards. Later, they were able to recognize the image for which they had been rewarded. The sheep could even recognize images of faces shown at an angle, though their ability to do so declined by about 15 percent – the same rate at which a human's ability to perform the same task declines.

    “Anyone who has spent time working with sheep will know that they are intelligent, individual animals who are able to recognize their handlers,” said Professor Jenny Morton, who led the Cambridge study. “We've shown with our study that sheep have advanced face-recognition abilities, comparable with those of humans and monkeys.”

    Recognizing faces is one of the most important social skills for human being, and some disorders of the brain, including Huntington's disease, affect this ability.

    “Sheep are long-lived and have brains that are similar in size and complexity to those of some monkeys. That means they can be useful models to help us understand disorders of the brain, such as Huntington's disease, which develops over a long time and affects cognitive abilities. Our study gives us another way to monitor how these abilities change.” Morton said.

    In the kitchen of my mother's houses there has always been a wooden stand (木架)with a small notepad(记事本)and a hole for a pencil.

    I'm looking for paper on which to note down the name of a book I am recommending to my mother. Over forty years since my earliest memories of the kitchen pad and pencil, five houses later, the current paper and pencil look the same as they always did. Surely it can't be the same pencil. The pad is more modern, but the wooden stand is definitely the original one.

    "I'm just amazed you still have the same stand for holding the pad and pencil after all these year." I say to her, walking back into the living-room with a sheet of paper and the pencil. "You still use a pencil. Can't you afford a pen?"

    My mother replies a little sharply. "It works perfectly well. I've always kept the stand in the kitchen. I never knew when I might want to note down an idea, and I was always in the kitchen in those days."

    Immediately I can picture her, hair wild, blue housecoat covered in flour, a wooden spoon in one hand, the pencil in the other, her mouth moving silently. My mother smiles and says, "One day I was cooking and watching baby Pauline, and I had a brilliant thought, but the stand was empty. One of the children must have taken the paper. So I just picked up the breadboard and wrote it all down on the back. It turned out to be a real breakthrough for solving the mathematical problem I was working on."

    This story—which happened before I was born—reminds me how extraordinary my mother was, and is, as a gifted mathematician. I feel embarrassed that I complain about not having enough child-free time to work. Later, when my mother is in the bathroom, I go into her kitchen and turn over the breadboards. Sure enough, on the back of the smallest one, are some penciled marks I recognize as mathematics. Those symbols have traveled unaffected through fifty years, rooted in the soil of a cheap wooden breadboard, invisible(看不到的)exhibits at every meal.