Leonardo da Vinci was born on April 15, 1452 in Italy. He is best known as an artist today. One of his famous paintings is called Mona Lisa. However, Leonardo had many other natural abilities. He was also a great inventor. Many of his inventions have become important in modern day life. Although Leonardo hated war, he invented many different machines used for wars. His most special invention was the machine gun, which was produced and used in war many years later.

    By watching the way birds fly, Leonardo tried to find out the secret of f lying. Among his sketches we can see several objects. We consider them as modern flying machines.Leonardo spent many hours thinking about how to make good use of time. He developed ideas for labor-saving machines like cutting machines.

    Leonardo was a strange man. He didn't eat any meat, which was unusual in those times. He never published his ideas and scientific discoveries. He usually used mirror writing, which looks like writing in a mirror, starting from the right side of the page and moving to the left.

    We have very little of his work today. Leonardo finished only a few of his paintings. He left many unfinished because he thought they were not perfect. No one in his life time knew how great Leonardo was. We now believe, however, that he was one of the cleverest men the world has ever known.

    When my brother and I were children, we spent a few weeks each summer in the countryside with our uncle. He was a geologist（地质学家） and loved to go on long walks to find stones to his collection in his spare time. We often followed him.

    One day, we left early, and this time, our uncle had bought us backpacks to help him carry the sample（样本）. The whole day, we walked around the countryside, and every now and then, our uncle put stones in our bags. We were a bit surprised that he also took some stones out from our bags at times, but we thought maybe he had just found better samples than the ones we already had.

    When we reached the house in the late afternoon, we were tired out. The backpacks were so heavy that we gave a big sigh of relief when we put them on the ground.

    Yet our uncle's backpack was half-empty.

    "Why did you give us so many stones?" we asked.

    "I didn't. You did, "he said, "You did not know it, but I made you go through a little attitude（态度） test today."

    "What do you mean an 'attitude test'?" we wondered. "It is something someone once did to me. You see, I listened to every word you said. And whenever you complained about anyone or anything, I added a stone to your bags. And whenever you talked about something with an attitude of gratitude（感恩） and positive（正面的） thinking, I took out a stone. And now look at your backpacks."

    We did. They were full.

    "Your negative（负面的） thoughts are like stones. You carry them in your mind just like those stones in a backpack. The more negative thoughts you have, the heavier your mind is. So look at those bags and start paying attention to what you say and how you say things."

    This little lesson was one of the most important I ever had. And I remember my uncle with great love for teaching us one of the most important lessons in life-the power of attitude.

    A kind of little cars may some day take the place of today's cars. If everyone drives such cars in the future, there will be less pollution. There will also be more space for parking cars in cities, and the streets will be less crowded. Three such cars can fit in the space now needed for one car of the usual size.

    The little cars will cost much less to own and to drive. Driving will be safer too, as these little cars can go only 65 kilometres an hour. The cars of the future will be fine for getting around a city, but they will not be useful for long trips. Little cars will go 450 kilometres before needing to stop for more gas (汽油).

    If big cars are still used along with the small ones, two sets of roads will be needed in the future. Some roads will be used for the big, fast cars and other roads will be needed for the slower, small ones.

    It's Friday today and we have an art class. But we don't have it at school. Where do we have it? Do you know? We have the class in the1It is our first time to have a class outside, so we are very2

    In the morning, our art teacher, Mrs. Wang3the classroom and says, "Boys and girls, today we'll have a class in the zoo. You can see your favorite animals and draw pictures of4there."

    Then we take a bus to the zoo. After we5there, we see so many animals. Some6eat bamboo (竹子). They are so cute. Tom7a picture of them. Jenny's favorite animals are monkeys (猴子). She wants to see them first.8those monkeys are in the trees. They don't come9, so Jenny can't see them. She doesn't know what to do. Peter is very10.He asks Jenny to give (给) these monkeys some bananas. Then all the monkeys come to them. All of us are happy to have the class in the zoo.