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    You may like chewing gum (口香糖) after meals to stop your breath smelling bad; or your mother might use a special neutralizer (调理剂) to protect her permed hair (烫发). But have you thought about the chemical principles behind such everyday actions?

    On March 2, the Senior 3 students from the IB (International Baccalaureate, 国际文凭) classes at Beijing Huijia Private School presented their discoveries, all in fluent English. This kind of seminar is held every year to show the achievements of the IB chemistry experiment lessons offered by the school. IB is a qualification based on a common curriculum (课程) for students aged 16-18 in any country and is recognized by universities everywhere.

    "Once I saw an advertisement for xylitol (木糖醇) gum," recalled Zhang Xinju. "Suddenly an idea came to my mind: are there any chemical reactions when the xylitol is working on our teeth?"

    Zhang and his partner Bu Xuan visited several hospitals to try and find out. "Doctors know that xylitol can protect teeth, but few could explain how the chemical reactions happen," said the 17-year-old boy.

    Presenting the results of their research in English to an audience of Chinese and foreign judges was never a problem for the students.

    "Textbooks for IB students are in English, and our teachers speak in English," explained Wei Duan and Han Yu, whose research topic was "The Acid-Base Reaction (酸碱反应) in the process of Hair-Perming".

    "In Senior 1 we often referred to Chinese textbooks, but we found we could understand and express it all in English by the second year."

    Lu Jiang, the school's IB chemistry teacher and China's only IB vice-examiner, is proud that her students can apply scientific theories they learn in class to daily life.

    "You might have learned these facts from you kindergarten teachers, but few think about the theories behind them," Lu said. "This kind of practice is intended to develop the scientific thinking they will need in their future studies."

    Dolphins (海豚) live in a dark underwater world. It's often impossible to see each other or anything else around them, so sound plays an important role in their survival. To communicate with each other, dolphins produce all kinds of sounds.

    Only other dolphins understand what the sounds mean. Scientists haven't uncovered their secret communication, except for one kind of whistle. It might last less than a second, but this whistle is a big deal. Why? Because these whistles are actually names of dolphins — and every dolphin has one. Scientists call these sounds a “signature whistle.” When other dolphins hear the whistle, they know which dolphin is calling.

    Dolphins often hunt by themselves but still need to stay connected to the group. Since they can't always see each other, dolphins use their signature whistles to check in with other dolphins hundreds of yards away. “In coastal areas, dolphins exchange whistles even when they're a third of a mile apart,” says Greg Campbell, who studies animals. That means dolphins shout out to group members that might be nearly five football fields away.

    What's amazing is who names the baby dolphin. Not the mother. Not an auntie dolphin or another group member. Scientists believe the baby dolphin itself comes up with the signature whistle. Like human babies, a baby dolphin plays with sounds throughout its first year. While testing its sound skills, a baby dolphin is doing something amazing. It's creating or figuring out its signature whistle. How or why it chooses its signature whistle is not clear. Studies show that most of the time the signature whistle is nothing like its mother's or group members' whistles.

    When the baby dolphin is about a year old, its signature whistle is set. It repeats it often so the other dolphins learn to recognize it.

    Deciphering(破译) dolphin names is just the beginning of figuring out what dolphins communicate about. Do they chat about sharks? Discuss the tides? Maybe they even have a name for people. Someday scientists are to decipher the rest of dolphins' communication.

    Getting paid to stay in bed all day sounds pretty good. But what if someone offered you $23,000 to stay in bed for two months? That's the deal that are search team is offering to 24 volunteers.

    Researchers are looking for volunteers to help them study the influences of weightlessness on the human body by spending 60 days lying down. Lying in bed isn't exactly the same as being weightless, but the influences on the human body are similar.

    When astronauts spend a long time in an environment with no gravity(重力), like the International Space Station (ISS),their bodies are affected in many ways. After a couple of months on the ISS, astronauts' hearts don't beat as hard. Their muscles（肌肉）become weaker because they no longer have to work against gravity. Their bones may break more easily. There may also be changes in the astronauts' sleep habits.

    Dr. Arnaud Beck, the researcher in charge of the study, said his goal is to measure the influences of weightlessness, and also to find ways to prevent problems. The study will take 88 days altogether. During the first two weeks the volunteers will be tested to establish(确定) their levels of fitness. Then they will spend 60 days lying in bed with their heads slightly lower than their bodies. They will have to do everything while lying down, including brushing their teeth and going to the bathroom. Dr. Beck said the rule is that they must have at least one shoulder touching the bed at all times. Half of the volunteers in the study will be taking capsules(胶囊) containing special food supplements（增补物）several times a day to see if they help reduce the health problems caused by weightlessness. The last two weeks of the study will be spent trying to let the volunteers recover. Volunteers must be men between the ages of 20 and 45 who are in perfect health. They must be non-smokers.

    The study will take place from September 1^st to November. The first two days are the time for volunteers to sign in.

    Al was a skilled artist. One night, his older son developed a serious stomachache. Neither Al nor his wife took the condition seriously. But it was actually acute appendicitis (急性阑尾炎), and the boy died suddenly that night.

    Knowing the death could have been prevented if he had realized the seriousness of the situation, Al's emotional health became worse. Worse still, his wife left him a short time later, leaving him alone with his six-year-old younger son. The hurt and pain of the two situations were more than Al could handle, and he turned to alcohol (酒) to avoid the pain. Gradually Al became an alcoholic (酒鬼) and began to lose everything he had. Finally, Al died alone in a San Francisco motel room.

    When I heard of Al's death, I felt sorry for him. “What a complete failure!” I thought. “What a totally wasted life!”

    As time went by, I began to rethink my earlier judgment. I knew Al's son, Ernie, one of the kindest and most caring men I have ever known. I watched Ernie with his children and saw the free flow of love between them. I knew that kindness and caring had long come from somewhere.

    One day I worked up my courage to ask him. “I'm really puzzled by something,” I said. “I know your father was basically the only one to raise you. What did he do so that you became such a special person?”

    Ernie sat quietly and thought for a few moments. Then he said, “From my earliest memories as a child until I left home at 18, Al came into my room every night, gave me a kiss and said, 'I love you, son.'”

    What a fool I had been to judge Al as a failure. He had not left any material possessions (财产) behind. But he had been a kind loving father, and he left behind one of the finest, most giving men I have ever known.

My First Day of School

    Fear started taking over, I was walking into my first school in America. I had traveled a long distance from India in order to join my parents, who had been for three years, hoping America would help my future. My father decided that I would be better off going to school here, so I enrolled(登记)in the local high school in my new town.

    I was afraid how I would do. On the first day, I went to my second period class after I had missed my first. With anxiety, I reached for the door, opening it slowly. Without paying attention to my classmates, I went straight to the teacher and asked if this was the right class. With a soft voice he answered. "Yes." His voice comforted me a little. He gave me a sheet called Course Requirements, which I would never get in India because we didn't have anything like that. Then he asked me to choose where I would sit. I didn't actually want to pick a seat. In India we had fixed seats, so I never needed to worry about that. I spent the rest of the class taking notes from the image produced by the overhead projector. In Indian schools, we didn't use the technology we had. We had to take notes as the teacher spoke.

    It was noon. I was very confused about when I would have lunch. I went to my next class and the bell rang as I entered. I went through the regular process of asking the teacher if I was in the right class. She said, "It's still fourth period."

    "But the bell just rang," I said.

    Changing from a gentle tone to a harsher(刺耳的)one, she said, "That is the lunch bell, young man."

    I apologized. Without another word I headed for the cafeteria. I felt lucky because we didn't have this in India. Every confusion seemed like a barrier I had to get through to reach my goal. At the end of the day, I was on my way to the bus which we didn't have in India either. I spotted my bus and sat down inside happily. I was thinking, today wasn't so bad.

    A few years ago, my husband Charlie and I had marital problems. Growing family responsibilities and financial worries took a toll on us and we began arguing frequently, often late into the night.

    However, neither of us could take the step that would end our eleven-year marriage and bring heartbreak to our three young children. Deep down we knew we still loved each other, so we determined to work it out. Through countless discussions, we began to close the gulf. The more honest we were, the closer we became.

    When I felt we were reaching solid ground, I asked my husband to give me an "eternity (永恒) ring". It was not so much the ring I wanted; it was the reassurance (保证) I thought it would bring.

    We went shopping on a beautiful summer day. We walked hand in hand along a row of jeweler's shops. Finally I found a ring I liked. While waiting for it to be adjusted, the jeweler took my left hand and glanced at my engagement ring. "May I clean it for you?" he asked. "It really doesn't sparkle like it used to." Charlie said as I slipped the ring off my finger. A few minutes later the jeweler was back. The ring shone like new!

    On the drive home, I didn't take my eyes off it. I forgot all about the eternity ring. I just couldn't believe how this old ring suddenly sparkled the way it had the day Charlie gave it to me. I had taken it for granted these past years, but with a little polish it could still make my heart beat fast.

    And that's the way it is with a marriage. You have to work at keeping it polished and new, or else the grime (污垢) of the passing years will hide the joy. I put my hand on the seat between us and spread my fingers. Charlie covered my hand with his. I felt I was lucky to be able to see the sparkle in something gold when I thought I needed something new.