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（生理节奏）, 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 inner clocks direct changes in temperature, body chemicals, hunger, sleepiness and more.

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

    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 in tests.

    "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 Program at Brigham and Women's Hospital in Boston.

    One way to learn about how our body clocks tick is to mess them up and see what happens. That's what neurologist（神经病学家）Frank Scheer and his workmates did in a recent study.

    Staying up night after night, their studies suggest, could make kids extra hungry and more likely to gain weight. And regularly sleeping too little, Scheer says, may be one cause of the recent increase in childhood obesity.

    The Healthy Habits Survey（调查）shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.

1). How many times did you brush your teeth yesterday?

Finding：A full 33% of seniors brush their teeth only once a day.

Step：Remove the 300 types of bacteria in your mouth each morning with a battery-operated toothbrush. Brush gently for 2 minutes, at least twice a day.

2). How many times did you wash your hands or bathe yesterday?

Finding：Seniors, on average, bathe fewer than 3 days a week. And nearly 30%wash their hands only 4 times a day-half of the number doctors recommend.

Step：We touch our faces around 3, 000 times a day-often inviting germs（病菌）to enter our mouth, nose, and eyes. Use toilet paper to avoid touching the door handle. And, most important, wash your hands often with hot running water and soap for 20 seconds.

3). How often do you think about fighting germs?

Finding：Seniors are not fighting germs as well as they should.

Step：Be aware of germs. Do you know it is not your toilet but your kitchen sponge（海绵）that can carry more germs than anything else? To kill these germs, keep your sponge in the microwave for 10 seconds.

    The values of artistic works, according to cultural relativism（相对主义）, are simply reflections of local social and economic conditions. Such a view, however, fails to explain the ability of some works of art to excite the human mind across cultures and through centuries.

    History has witnessed the endless productions of Shakespearean plays in every major language of the world. It is never rare to find that Mozart packs Japanese concert halls, as Japanese painter Hiroshige does Paris galleries. Unique works of this kinds are different from today's popular art, even if they began as works of popular art. They have set themselves apart in their timeless appeal and will probably be enjoyed for centuries into the future.

    In a 1757 essay, the philosopher David Hume argued that because “the general principles of taste are uniform（不变的）in human nature,” the value of some works of art might be essentially permanent. He observed that Homer was still admired after two thousand years. Works of this type, he believed, spoke to deep and unvarying features of human nature and could continue to exist over centuries.

    Now researchers are applying scientific methods to the study of the universality of art. For example, evolutionary psychology is being used by literary scholars to explain the long-lasting themes and plot devices in fiction. The structures of musical pieces are now open to experimental analysis as never before. Research findings seem to indicate that the creation by a great artist is as permanent an achievement as the discovery by a great scientist.

    Incredible Women You Didn't Learn About in History Class

    Here are the stories of women you may not know about, but definitely should

    Maria Sibylla Merian

    Born in Germany in 1647, Merian was fascinated by insects, and she began collecting, studying, and drawing them when she was as young as 13. She was one of the few naturalists of her time to actually study live insects. It was through her study of caterpillars(毛毛虫) that she discovered the truth about their life cycles. Her work provided major contributions to the field of entomology（昆虫学）。

    Murasaki Shikibu

    Murasaki Shikibu, a Japanese woman, was widely considered to be the world's first novelist. She was a noble woman living in Japan around the year 1000 AD. She wrote a two-part novel called The Tale of Genji, which tells a riches-to-rags story about the son of a Japanese emperor forced to live as a common man. The Tale of Genji is widely considered to be a masterpiece of Japanese literature.

    Ada Lovelace

    Ada was working to design early computing machines that she hoped would be able to quickly solve math problems. In addition to designing this early computer program, she also was first to suggest that these computers might be able to do more than, well, calculate. She imagined them doing everything, from producing images to composing music.

    Lucy Stone

    Born in 1818, Stone married a fellow activist and changed her name, but decided to change it back a year later. She held the belief that "a wife should no more take her husband's name than hers." She became the first American married woman to keep her maiden name for her entire life. Stone was also one of the founding members of the American Equal Rights Association and fought for the ending of slavery.

    In every British town, large and small, you will find shops that sell second-hand goods. Sometimes such shops deal mostly in furniture, sometimes in books, sometimes in ornaments（装饰） and household goods, sometimes even in clothes.

    The furniture may often be "antique", and it may well have changed hands many times. It may also be very valuable, although the most valuable piece will usually go to the London salerooms, where one piece might well be sold for hundreds of thousands of pounds. As you look around these shops and see the polished wood of chests and tables, you cannot help thinking of those long-dead hands which polished that wood, of those now-closed eyes which once looked at these pieces with love.

    The books, too, may be antique and very precious; some may be rare first printings. Often when someone dies or has to move house, his books may all be sold, so that sometimes you may find whole libraries in one shop. On the border between England and Wales, there is a town which has become a huge bookshop as well. Even the cinema and castle have been taken over, and now books have replaced sheep as the town's main trade.

    There are also much more humble shops, sometimes simply called "junk shops", where you can buy small household pieces very cheaply. Sometimes the profits（利润）from these shops go to charity. Even these pieces, though, can make you feel sad; you think of those people who once treasured them, but who have moved on to another country or to death.

    Although the British do not worship（崇拜）their ancestors, they do treasure the past and the things of the past. This is true of houses as well. These days no one knocks them down; they are rebuilt until they are often better than new. In Britain, people do not buy something just because it is new. Old things are treasured for their proven worth; new things have to prove themselves before they are accepted.

The easiest way to love yourself is to treat yourself like your own BFF (Best Friend Forever). {#blank#}1{#/blank#} Quite simply, this means you need to recognize your own self-worth and live your own life as honestly as you can. Read on to learn some strategies so you can embark on a journey of loving yourself.

{#blank#}2{#/blank#}Negative thoughts often come from outside people whose opinions we value and from whom we seek love and acceptance. Trace down the core of those negative thoughts and tell yourself a different story. Think about what you would say to a close friend who said those things about themselves.

Accept your flaws as part of who you are. Everything you've done and everywhere you've been is a part of who you are. {#blank#}3{#/blank#} Instead, accept that they're all parts of the same whole. When you love yourself, you love all of you because you wouldn't have the good without the bad.

Focus on your effort rather than the result to control perfectionism. If you expect yourself to be perfect for ever, you'll never be pleased with anything you produce. {#blank#}4{#/blank#} Try to appreciate the work you put into completing a task, rather than looking for flaws in what you done.

Practice gratitude for good things. Its human nature to see negative things as bigger and more important than positive things, but this also does tremendous damage to your self-esteem. When you find yourself focusing on negative or less favorable events in your life, immediately try to name 3 to 5 things that you can be grateful for. {#blank#}5{#/blank#}

A. This can lead to low self-esteem.

B. Pay attention to negative thoughts.

C. Let go of negative thoughts about yourself.

D. Self-love isn't about fixing all the "bad" things about yourself.

E. Look for the positive side even when bad things happen to you.

F. Usually, it might seem like it's easier to love others than to love yourself.

G. Actually, it's tough to build healthy relationships if you don't love yourself first.