Some friends are playing hide-and-seek (捉迷藏) at Mr. Green' home. They play in Mike's room. It's time for Lily to find her friends. Lily first finds Sally.Sally is behind the door. Then, Lily sees Bob. Bob is under the table. Mike is under the table, too. Now it's time to find David and John. David's hat is on the sofa. Is David under the sofa? No, he isn't. John's schoolbag is on the chair, but he isn't there.“Where are they?”Lily thinks.Shh! Don't let her know. They are under the bed!

B

    I have a twin brother, Bob. He is taller than me. His hair is shorter than mine. Many people think we must have many things in common. But in fact this is not true. Bob is more outgoing than me. When my parents' friends come to our house, Bob often sits there and talks to them. But I often sit there and say nothing. Bob likes reading, cooking and drawing. I just like swimming and playing basketball. He has more hobbies than me, but he is not as athletic(擅长运动的) as me. Because Bob does better than me at school, my mom often says to me, “Bob is younger than you, but he can get better grades, you should learn from him.” We both like eating fast food and listening to music.

    What was discovered by accident? The answer is penicillin (青霉素). It kills germs. By killing germs, it saves lives. Suppose you are sick. You go to a doctor. She examines you. She says you have a “staph” infection (葡萄球菌感染). She gives you some medicine. You take it. The medicine knocks out the staph. Soon you are well. Before penicillin, this would not happen. Staph was almost sure death.

    Everyone wanted a medicine. Laboratories worked day and night. They grew the staph in small dishes. Then they tried to kill it. Nothing worked.

    The laboratory dishes had covers on them. They kept things from falling into dishes. Molds (霉菌) were a big worry. They are always in the air. You can't see them. They're too small. There are thousands of different molds. Molds can make an experiment (实验) fail. That's why dishes are covered.

    Dr. Alexander Fleming was working to kill the staph germ. He worked for years. One day he took a cover off a dish. He looked inside. There was a thick growth of staph germ. There was also some mold. Then he saw something strange. Where the mold was, there was no growth of staph. This is what Fleming probably thought. “By accident, I found a mold to kill the dreaded staph.”

    This is how penicillin was found. But here's the real miracle (奇迹). There are thousands of kinds of molds. But only one kind can kill staph. The mold must have fallen into the dish a few days before. The cover was probably off only a few seconds (秒). In those few seconds the right mold fell into the right dish. Another man might have thrown the dish away. But Fleming was very careful and smart. He understood what the mold did. How lucky the humans were!

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    My name is Sam. I joined a club called "passing help" last month. Now let me tell you why I joined it.

    One evening this May, on my way home my old car broken down. It was 25 miles from my home. I wanted to get a ride(搭便车), but there was no car. It was also hard to take a taxi. I decided to take a bus home. I went to a bus stop nearby.

    After a while, a bus came, but it did not go to my town. The bus driver was a young woman. She was kind and she told me which bus I should take. I waited there for about thirty minutes, but no bus came. At last a car came to me and a woman came out of the car. She was just the bus driver.

    "When I reached the bus station, I got to know that the bus to your town couldn't come, so I returned here. I just can't leave you here," she said, "Get in my car and l will take you back to your home."

    "It is a long way." I said.

    "Come on, sir," she said, "Let's go."

    On the way she told me a story. A few days ago，there wasn't gas(汽油)  in her car. An old man drove her up to a gas station and then back to her car.

    When we got to my home, I wanted to give her some money to thank her, but she didn't accept. "I only want to help others and do something nice for somebody. Pass it along." she said.