On May 23, 1989, Stefania Follini came out from a cave at Carlsbad, New Mexico. She hadn't seen the sun for eighteen and a half weeks. Stefania was in a research program, and the scientists in the program were studying body rhythms. In this experiment Stefania had spent 130days in a cave, 30 feet in depth.

    During her time in the cave, Stefania had been completely alone except for two white mice. Her living place had been very comfortable, but there had been nothing to tell her the time. She'd had no clocks or watches, no television or radio. There had been no natural light and the temperature had always been kept at 21℃.

    The results were very interesting. Stefania had been in the cave for over four months, but she thought she had been there for only two. Her body clock had changed. She hadn't kept to a 24-hour day, she had stayed awake for 20～25 hours and then had slept for 10 hours. She had eaten fewer meals and had lost 171bs in weight as a result! She had also become rather depressed.

    How had she spent her time in the cave? As part of the experiment she'd done some physical and mental tests. She'd recorded her daily activities and the results of the tests on a computer. This computer had been specially programmed for the project. Whenever she was free, she'd played cards, read books and listened to music. She'd also learned French from tapes.

    The experiment showed that our body clocks are affected by light and temperature. For example， the pattern of day and night makes us wake up and go to sleep. However, people are affected in different ways. Some people wake up naturally at 5:00 a.m., but others don't start to wake up till 9:00 or 10:00 a.m. This affects the whole daily rhythm. As a result the early risers are at their best in the late morning. The late risers, on the other hand, are tired during the day and only come to life in the afternoon or evening!

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    Last month I was lucky enough to have a chance to make a trip into space with my friend Li Yanping, an astronomer. We visited the moon in our spaceship!

    Before we left, Li Yanping explained to me that the force of gravity would change three times on our journey and that the first change would be the most powerful. Then we were off. As the rocket rose into the air, we were pushed back into our seats because we were trying to escape the pull of the earth's gravity. It was so hard that we could not say anything to each other. Gradually the weight lessened and I was able to talk to him. "Why is the spaceship not falling back to the earth? On the earth if I fall from a tree I will fall to the ground." I asked. "We are too far from the earth now to feel its pull, " he explained, "so we feel as if there is no gravity at all. When we get closer to the moon, we shall feel its gravity pulling us, but it will not be as strong a pull as the earth's. " I cheered up immediately and floated weightlessly around in our spaceship cabin watching the earth become smaller and the moon larger.

    When we got there, I wanted to explore immediately. "Come on," I said. "If you are right, my mass will be less than on the earth because the moon is smaller and I will be able to move more freely. I might even grow taller if I stay here long enough. I shall certainly weigh less!" I laughed and climbed down the steps from the spaceship. But when I tried to step forward, I found I was carried twice as far as on the earth and fell over. "Oh dear," I cried, "walking does need a bit of practice now that gravity has changed." After a while I got the hang of it and we began to enjoy ourselves.

    During the cold winter days, there are some interesting festivals in the world. Look at the following ones.

    Harbin Ice and Snow Festival

    Place: China

    Time: January 5 to February 5

    People build incredible things out of ice and snow, decorating them with lights.

    The Carnival of Venice

    Place: Italy

    Time: between February and March

    One of the most beautiful festivals in the world, people wear masks and elaborate costumes to hide differences among classes, and there are contests for the best costumes.

    Holi Festival

    Place: India

    Time: late February/ March, on the last full moon day

    Hindus and Sikhs, in India, Nepal, and Sri Lanka celebrate the main day of this incredibly fun 16-day festival by throwing colored powder and water at each other.

    Sundance Film Festival

    Place: Utah, the US

    Time: end of February

    The largest independent film festival in the US. Watch both feature films and shorts. You need to buy a ticket.

    When it comes to the most famous 20^th century painters of the United States, Grandma Moses should be mentioned, although she did not start painting until she was in her late seventies. As she once said to herself:" I would never sit back in a rocking chair, waiting for someone to help me." No one could have had a more active old age.

    She was born on a farm in New York State, one of five boys and five girls. At 12 she left home and was in domestic service until at 27 she married Thomas Moses, the hired hand of one of her employers. They farmed most of their lives, first in Virginia and then in New York State, at Eagle Bridge. She had ten children, of whom five survived; her husband died in 1927.

    Grandma Moses painted a little as a child and made embroidery(刺绣) pictures as a hobby, but only changed to oils in old age because her hands became too stiff(僵硬的) to sew and she still wanted to keep busy and pass the time. Her pictures were first sold at the local drugstore and at a market and were soon noticed by a businessman who bought all that she painted. Three of the pictures were exhibited(展览) in the Museum of Modern Art, and in 1940 she had her first exhibition in New York. Between the 1930's and her death, she produced some 2,000 pictures: careful and lively portrayals of the country life she had known for so long, with a wonderful sense of color and form. "I think really hard till I think of something really pretty, and then I paint it" she said.

    Painkillers (止痛药) are turning out to be a real pain: according to a new study in the British Medical Journal. Taking them for just a week can increase your risk of heart attack by 50%. The research suggested that the risk related to the use of certain drugs was greatest with higher doses (服用量) and during the first month of use. The potential risk may increase by 75% for medicines like ibuprofen (布洛芬) and naproxen, and more than 100% for rofecoxib.

    It all sounds bad but, your risk is very low, — say, one in a million — a 100% increase means you still only have a two in a million chance. Of course, all painkilling medication that works can have side effects — nothing is safe and effective. Paracetamol (扑热息痛) has very few unless taken too much, in which case it can cause serious liver danger, but it isn't very effective. Drugs like opiates are strong painkillers but easy to be addicted and often have other bad effects. Maybe you find that you are in a dilemma now. But don't despair; you can refer to a pain clinic for some professional guidance. For ongoing pain, music and exercise may be the best choices to help you reduce the feeling of it.

    Scientist at Harvard have recently done a quite horrible study on mice. They made the mice experience extremes of hot and cold, applied pressure to their back legs and injected the capsaicin (辣椒素) into their feet. And then they timed how long it took them to respond to the pain. Lack of sleep increased the discomfort, while stimulants (兴奋剂) such as caffeine made them less responsive to pain. This has been widely reported that a good night's sleep and a cup of coffee in the morning may help reduce pain.

    But anyway  don't throw the pills away because the study also shows taking small doses of drugs, such as for short periods of time can be effective and safe as long as your heart is in good condition.

My clder brother Steve, in the absence of my father who died when I was six, gave me important lessons in values that helped me grow into an adult.

For instance, Steve taught me to face the results of my behavior. Once when I returned in tears from a Saturday baseball game, it was Steve who took the time to ask me what happened. When I explained that my baseball had scared through Mrs. Holt's basement window, breaking the glass with a crash, Steve encouraged me to confess(认罪) to her. After all, I should have been playing in the park down Fifth Street and not in the path between buildings. Although my knees knocked as I explained to Mrs. Holt, I offered to pay for the window from my pocket money if she would return my ball.

I also learned from Steve that personal property is a sacred(神圣的) thing. After I found a shiny silver pen in my fifth-grade classroom, I wanted to keep it, but Steve explained that it might be important to someone else in spite of the fact that it had little value. He reminded me of how much I'd hate to lose to someone else the small dog my father carved from a piece of cheap wood. I returned the pen to my teacher, Mrs. Davids, and still remembered the smell of her perfume as she patted me on my shoulder.

Yet of all the instructions Steve gave me, his respect for life is the most vivid in my mind. When I was twelve I killed an old brown sparrow in the yard with a BB gun. Excited with my accuracy. I screamed to Steve to come from the house to take a look. I shall never forget the way he stood for a long moment and stared at the bird on the ground. Then in a dead, quiet voice, he asked, "Did it hurt you first, Mark?"I didn't know what to answer. He continued with his eyes firm," The only time you should even think of hurting a living thing is when it hurts you first. And then you think a long. long time." I really felt terrible then, but that moment stands out as the most important lesson my brother taught me.