Perhaps the most interesting person I have ever met in my life is an Italian professor of philosophy who teaches at the University of Pisa. 1 I last met this man eight years ago, I have not forgotten his 2 qualities. First of all, I respected his 3 to teaching. Because his lectures were always well-prepared and clearly delivered, students crowded into his classroom. His followers liked the fact that he 4 what he taught. Furthermore, he could be counted on to explain his ideas in an 5 way, introducing such aids to 6 as oil paintings, music, and guest lecturers. Once he 7 sang a song in class in order to make a point clear. 8, I admired the fact that he would talk to students outside the classroom or talk with them 9 the telephone. Drinking coffee in the café, he would easily make friends with students. Sometimes he would 10 a student to a game of chess. 11, he would join student groups to discuss a variety of 12: agriculture, diving and mathematics and so on. Many young people visited him in his office for 13 on their studies; others came to his home for social evenings. Finally, I was 14 by his lively sense of humor. He believed that no lesson is a success 15, during it, the students and the professor 16 at least one loud 17. Through his sense of humor, he made learning more 18 and more lasting. If it is 19 that life makes a wise man smile and a foolish man cry, 20 my friend is indeed a wise man.

    Try this: For an entire day, forget about the clock. Eat when you're hungry and sleep when you're tired. What do you think will happen?

    You may be surprised to find that your day is much like most other days. You'll probably get hungry when you normally eat and tired when you normally sleep. Even though you don't know what time it is, your body does.

    These patterns of daily life are called circadian rhythms, and they are more than just habits. Inside our bodies are several clocklike systems that follow a roughly 24-hour cycle. Throughout the day and night, our internal clocks direct changes in temperature, body chemicals, hunger, sleepiness and more.

    Everyone's rhythms are unique, which is why you might like to stay up late while your sister always wants to go to bed early. But overall, everyone is programmed to feel tired at night and energetic during the day.

    Scientists have known for a long time that the light of day and the dark of night play important roles in setting our internal（内部的） clocks. Now, new discoveries are giving scientists insights into how these clocks work.

    Learning about our body clocks may help scientists understand why problems arise when we act out of step with our circadian rhythms. For example, traveling across time zones can make people wake up in the middle of the night. Regularly staying up late can make kids do worse on tests and quizzes. And working shifts at night leads to higher rates of heart disease, diabetes and obesity.

    “There is a growing sense that when we eat and when we sleep are important parts of how healthy we are,” says Steven Shea, Director of the Sleep Disorders Research Program at Brigham and Women's Hospital in Boston.

    Scientists still aren't sure why the timing of sleep matters so much, Shea says. But research findings suggest that our circadian rhythms are more important than we give them credit for.

    “During the night, we are prepared to sleep,” Shea says. “During the day, we are prepared to eat and move around. If you reverse (颠倒)what you are doing, everything is out of phase. That can have unfavorable consequences.”

— I expect _______ over 200 students then.

1). 词数100左右，信的开头和结尾己为你写好;

2). 可以适当增加细节，以使行文连贯。

Dear Editor-in-Chief，

    My name is Li Hua and I'm writing to apply for the position of the student reporter you advertised in the 21^th Century.

    Looking forward to your reply.

Sincerely yours,

Li Hua

    Against the assumption that forest fires in Alaska, Canada and Siberia warm the climate, scientists have discovered that cooling may occur in areas where burnt trees allow more snow to mirror more sunlight into space.

    This finding suggests that taking steps to prevent northern forest fires to limit the release of greenhouse gases may warm the climate in northern regions. Usually large fires destroyed forests in these areas over the past decade. Scientists predict that with climate warming, fires may occur more frequently over next several centuries as a result of a longer fire season. Sunlight taken in by the earth tends to cause warming, while heat mirrored back into space tends to cause cooling.

    This is the first study to analyze all aspects of how northern fires influence climate. Earlier studies by other scientists have suggested that fire in northern regions speed up climate warming because greenhouse gases from burning trees and plants are released into the atmosphere and thus trap heat.

    Scientists found that right after the fire, large amounts of greenhouse gases entered the atmosphere and caused warming. Ozone（臭氧）levels increased, and ash from the fire fell on far-off sea ice, darkening the surface and causing more radiation from the sun to be taken in. The following spring, however, the land within the area of the fire was brighter than before the fire, because fewer trees covered the ground. Snow on the ground mirrored more sunlight back into space, leading to cooling.

    “We need to find out all possible ways to reduce the growth of greenhouse gases in the atmosphere.” Scientists tracked the change in amount of radiation entering and leaving the climate system as a result of the fire, and found a measurement closely related to the global air temperature. Typically, fire in northern regions occurs in the same area every 80 to 150 years. Scientists, however, found that when fire occurs more frequently, more radiation is lost from the earth and cooling results. Specifically, they determined when fire returns 20 years earlier than predicated, 0.5 watts per square meter of area burned are soaked up by the earth from greenhouse gases, but 0.9 watts per square meter will be sent back into space. The net effect is cooling. Watts are used to measure the rate at which energy is gained or lost from the earth.

    Each morning during fifteen- minute bath, I determined to cultivate a b+添加知识点ig, happy smile. I found out it had to be an honest-to-goodness smile from down deep 1 , an outward expression of happiness from within!

        Let's see how the smile muscles 2 me during the day. I would think of the things I had to be 3 for, work up a big smile and then enter. It 4 people when I passed them on the street to give them a 5 smile. Give every living soul you meet the best smile you have 6 smiled in your life, and see how much better you feel and look. It's one of the best ways to 7 worrying, and start living. When I began to do this, I found I became more welcome everywhere.

— Exactly. A flag often symbolizes the origin beliefs and culture.

    Here is an astonishing and significant fact: Mental work alone can't make us tire. It sounds absurd. But a years ago, scientists tried to find out how long the human brain could labor without reaching a stage of fatigue (疲劳). To the amazement of these scientists, they discovered that blood passing through the brain, when it is active, shows no fatigue at all! If we took a drop of blood from a day laborer, we would find it full of fatigue toxins(毒素) and fatigue products. But if we took blood from the brain of an Albert Einstein, it would show no fatigue toxins at the end of the day.

    So far as the brain is concerned, it can work as well and swiftly at the end of eight or even twelve hours of effort as at the beginning. The brain is totally tireless. So what makes us tired?

    Some scientists declare that most of our fatigue comes from our mental and emotional(情绪的) attitudes. One of England's most outstanding scientists, J.A. Hadfield, says, “The greater part of the fatigue from which we suffer is of mental origin. In fact, fatigue of purely physical origin is rare.” Dr. Brill, a famous American scientist, goes even further. He declares, “One hundred percent of the fatigue of sitting worker in good health is due to emotional problems.”

What kinds of emotions make sitting workers tired? Joy? Satisfaction? No! A feeling of being bored, anger, anxiety, tenseness, worry, a feeling of not being appreciated—those are the emotions that tire sitting workers. Hard work by itself seldom causes fatigue. We get tired because our emotions produce nervousness in the body.

—________. It's four years since I worked there.