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 daily life.

Although Leonardo hated war, he invented many different machines used for war. 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 flying. Among his sketch (素描) 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 very unusual in those times. He never published(发表) 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.

    Bob is an artist. He owns a house in New York. One afternoon when he drives home from work, his three children are playing in the garden. Some of his flowers are broken. The door of his wife's car is open, and the front door of the house is open, too.

    When he walks in the house, his house is messy. In the living room, the TV is on. Toys and clothes are everywhere. In the kitchen, dirty plates and bowls are in the sink(水槽). Breakfast food and dog food are everywhere. A broken glass is under the table.

    Bob runs fast and looks for his wife. He worries about her. Is she sick? He finds her in the bedroom. She is staying in the bed and reading a book. She looks at him and smiles.

    Bob ask, “What's up today?”

    She again smiles and answers, “You always ask me what I do today when you come home.”

    “Yes.” Says Bob.

    “Today I don't do it.” She smiles again.

    Have you ever saved money to do something special? Cindy Evans and her third-grade class are sure to answer, "Yes!"

    Cindy Evans works at Big Beaver Elementary School in Big Beaver, Pennsylvania. One day, she and her third-grade class read about the Great American Smokeout in Weekly Reader. The Smokeout is an event to help people give up smoking. The American Cancer Society runs it.

    "We read that about l million people give up smoking each year," said Ms Evans. Then her students asked her. "What does 1 million look like?" Ms Evans told her class the best way to see 1 million was to collect 1 million things.

    "I was thinking about collecting 1 million small things like erasers," said the teacher. But her students had a better idea: to collect 1 million pennies (分) and give them away to the American Cancer Society. Soon the class started their big job.

    Many people in the neighbourhood joined the students. According to Ms Evans, the bank in their neighbourhood had to keep more pennies because so many people were collecting them.

    That June, the class went to the office of the American Cancer Society with 1,177,500 pennies, or$11,775. They hoped that the money could help more people keep healthy.

    "The hound(猎犬)!" cries Holmes. "Come, Watson! Come."

    We run quickly over the moor(荒野). We hear one last cry. A man is lying on the ground. As we approach(靠近) we see the dead body of Sir Henry Baskerville. He is wearing his brown suit.

    "Oh, no!" says Holmes, "This man has a beard!"

    Indeed Selden is dead instead of Sir Henry.

    "So it is all clear to me. I remember that Sir Henry gave his old suit to Barrymore, and Barrymore probably gave it to Selden—his wife's brother."

    "Then Selden is dead because of this suit," says Holmes.

    "Think, Watson! Someone gives the hound some of Sir Henry's clothes—probably the boot from the hotel in London. The hound picks up Sir Henry's scent and runs after this poor man."

    Suddenly we see Stapleton walking towards us. He says, "There was a strange noise. I was worried about Sir Henry. I wanted to check if he was all right."

    "Really?" asks Holmes.

    Stapleton looks at Holmes. "Why, it is Mr. Sherlock Holmes, the famous detective! Can you solve the mystery of the Hound of the Baskervilles?"

    Holmes shrugs his shoulders," We cannot solve every mystery. Anyway I will return to London tomorrow."

    "Oh, will you return to London tomorrow?"

    "Yes."

    So Holmes and I walk off to Baskerville Hall and Stapleton walk to his home.

    Holmes thinks Stapleton is dangerous. But we have no proof that Stapleton is the murderer.

    "There are no marks on Sir Charles's body. We know that he died of fright, but we can't prove anything."

    "Things are becoming clear to me," Holmes says to Sir Henry. "It's a very difficult case. And you must help me to catch this hound."

    We are surprised to see one portrait(画像) of a thin man is Sir Hugo, the first victim of the Hound of the Baskervilles. And he's like both Sir Henry and Stapleton. "Stapleton is a Baskerville," replies Holmes. "So he wants to inherit(继承) the Baskerville fortune, and he…," I say. It's an important clue.

    One day, an 11-year-old girl asked her dad," What are you going to get me for my 15th birthday? "The father replied, "Don't worry about that. We still have plenty of time."

    But on a day after her 14th birthday, She passed out(昏倒) and was rushed to the hospital. The family learned that the girl had a serious heart disease and that she might die. At night, she asked her dad, "Daddy, have they told you that I am going to die?" The father replied, "No, you will live as long as anyone else." She wondered and asked, "How can you be sure?" He smiled to her and said," I just know it?"

    After the girl turned 15, She had a heart transplant (心脏移植手术). After she came back from the hospital, she found a letter on her bed. It said, "My dearest daughter, one day you asked me what I would give you for your 15th birthday. I wasn't sure then. But now you know that my present to you is my heart." The father had given his heart to his daughter.

    Parents are selfless (无私的). They even make great sacrifices to make their children grow up happily. Keep this in mind when you feel angry toward your parents. Always, they're just doing what they think best for you.