There was good news last week for people who struggle to get eight hours of sleep a night: they may not need so much shut-eye after all.

    Researchers from UCLA and elsewhere looked at sleep habits of remote hunter-gatherers in Tanzania, Namibia and Bolivia — groups with pre-industrial lifestyles whose sleep patterns are believed to reflect those of ancient humans. The researchers found that, on average, members of each group sleep a bit less than six and a half hours a night.

    The study, published in the academic journal Current Biology, indicates that “natural” sleep is less than eight hours a night and that modern society's numerous electronic distractions (分心) aren't necessarily to blame for people getting just six or seven hours of sleep.

    “The story that often gets out is that if you sleep for less than seven hours, you're going to die early,” he told me. “That's not true.”

    Yet Americans are addicted to getting more sleep — and on turning to medical shortcuts to help them.

    According to the Centers for Disease Control, as many as 70 million U.S. adults suffer from sleep disorders or sleeplessness. Only a third of Americans get the government's recommended seven to nine hours of sleep a night.

    About 9 million American adults use sleeping pills to help get a good night's rest, the CDC found. Siegel said the number of people relying on medicines “has gone up rather rapidly since then.”

    Industry consulting firm Global Data estimates that worldwide sales for sleeplessness medicines will run about $1.4 billion next year and reach $1.8 billion by 2023, recovering from lower sales in recent years because of cheaper generics(仿制药) hitting the market.

    Dr. Roy Artal, a sleep specialist in West Los Angeles, said it's understandable that busy people in today's go-go world would turn to medicines to speed up the sleep process. But all they're doing is building a reliance on powerful drugs for relatively little improvement.

    “There's no magic pill that makes us sleep when we want and wake up when we want,” Artal said. “The effects of sleeping pills tend to be modest.”

    He and other experts say the answer to sleeplessness isn't to be found in a pill bottle. It's in what's called “sleep hygiene (保健).”

    Six million people visit Grand Canyon in the US every year. For the purpose of helping project Grand Canyon for your fellow visitors and future generations, please follow the guidelines below.

    Camping

    To protect the park, camping is allowed only within permitted campgrounds. Permits are required for overnight camping at the North Rim. Advance booking can be received by mail. Please write: Information Center, P.O. Box 129, Grand Canyon, AZ 86023.

    Fires

    Because of the extreme fire danger, campfires are not allowed except at Mather and Desert View campgrounds. Collection of firewood is not allowed either.

    Hiking（远足）

    Please stay on permitted paths. Otherwise you may destroy desert plants. Pack out what you pack in, so you leave no signs of your visit. It is important to keep in mind that you are in a national park where wildlife exists.

    Weather

    The weather at Grand Canyon can change very quickly. With so much rock, lightning(闪电) causes a particular danger during sudden summer storms These storms also frequently bring floods inside valleys, a danger to hikers. Watch the skies and check daily weather reports.

    Wildlife

    Do not feed park wildlife. There have been a few cases at Grand Canyon National Park where deer(鹿) were purposely shot because there are plastic bags that left them sick and weak. Hungry deer car be danger and have kicked and bitten visitors at Grand Canyon. Some other animals will also beg and bite. For your own safety and the well-being of the animals, please do not feed wildlife, no matter how gentle they may appear.

    The clock struck eleven at night. The whole house was quiet. Everyone was in bed except me. Under the strong light, I looked sad before a huge pile of troublesome stuff that were called “books”. I was going to have my exam the next day. "When can I go to bed?" I asked myself. I didn't answer; as a matter of fact, I dared not.

    The clock struck twelve. "Oh, dear!" I cried, "five more books to read before I can go to bed!” We pupils are the poorest in the world. Dad does not agree with me on this. He did not have to work so hard when he was a boy.

    The clock struck one. I was quite hopeless now. I forgot all I had learnt. I was too tired to go on. I did the only thing I could. I prayed, “Oh, God! Please help me pass the exam tomorrow. I do promise to work hard afterwards, Amen.” My eyes were so heavy that I could hardly open them. A few minutes later, with my head on the desk, I fell asleep.

    A little boy discovered what looked like a map to an unknown place. He soon realized it was the beginning of an exciting treasure hunt.

    He found two pieces of paper along with the mysterious map. One was written with the instructions, “FIND THE WORDS.” The other piece of paper had several strange symbols scattered all over it.

    Dad, fortunately, was there to help his son figure out the mystery. He folded up the paper with the symbols on it, and together they formed a message, which had another set of instructions, “UNDER STEPS.” The smart little boy knew exactly what to do so he went to look under the steps of his house. Without too much effort, he found a box below the staircase.

    It didn't take him long to figure out what to do next: open it up! Inside the box were some very interesting objects, including another piece of a treasure map and two broken pieces of paper. These were the most interesting finds because they contained what appeared to be a collection of letters on them. Finally, they knew where the treasure was from the letters: IN THE BUSH UNDER YOUR YARD.

    After searching all over the yard, following several clues and wondering where everything would lead, the pair finally found what they had been looking for. And it was exactly what you would want after such an adventure: a treasure box!

    The pair pulled it out of the ground and cleaned away all the dirt. The dad put the box in front of his son, and the little boy couldn't contain his excitement. So he opened it up and finally found out what was inside.

    Inside was more treasure than any little boy could ever want. There were hundreds of coins and all sorts of pirate treasure, including what looks like a pearl necklace and some silver dishes.

    Tom Costello was once afraid of homeless Americans. “I was so afraid that if I saw a homeless person walking down the street, I'd cross the street,” he said.

    That changed seven years ago after his wife, Nancy, a volunteer at a homeless shelter, persuaded him to help with a holiday dinner for shelter residents. Tom remembered going to a store and buying socks for the residents. He knew many of them were in need of clothing.

    At the shelter, Tom said, he dropped a pair of socks into a bag for a woman. She asked him if she could have socks for a friend who wasn't with her that day. He gave her another pair. “She started to cry and told me that nobody had ever given her socks before,” Tom said, “Then she reached out and gave me a hug.” That experience at the shelter helped Tom end his fear of the homeless.

    It also led him to set up a group called “The Joy of Sox.”, which borrows from a name of a popular book. The group collects socks from donors and gives them mostly to shelters in the area where Tom and Nancy live. It has been expanding its reach and provides socks to homeless shelters in 21 states and other three countries now.

    Why socks? Tom explains that some Americans give food, coats and other clothing to shelters. But donating socks is not something most people think about. And, he said, socks are very helpful at keeping people warm, especially in cold weather. A man named Kiwi，who has lived in homeless shelters, said most of the time he could find enough food through shelters and soup kitchens. But socks were much more difficult to get, he noted.

    During my elementary school years, I used to compare my mom with my best friend Tiffany's mom.

    Tiffany's mom always gave her lots of money to buy the most fashionable clothes and favorite food. Her mom allowed her to do anything she liked. I really admired Tiffany. My mom didn't give me much pocket money and she always told me that I should behave myself. I was annoyed with her.

Whenever I didn't get what I wanted, I would complain to my mom, Tiffany's mom would give her that! I wish she were my mom. Every time, my mom would calmly say "Poor Tiffany". I couldn't understand her. "She shouldn't be feeling sorry for Tiffany!" I thought. "She should be feeling sorry for me."

One day, I couldn't help saying to Mom, "Poor Tiffany? Lucky Tiffany! She gets everything she wants! Why do you feel sorry for her?" I burst into tears.

My mom sat down next to me and said softly. "Yes, I do feel sorry for her. I have been teaching you a lesson that she will never be taught."

I looked up at her. "What are you talking about?"

Mom said with care, "One day she will really want something. Maybe she'll find out that she can't have it. Her mother won't always be around to give her money, and what's more, money can't buy everything."

She continued, "I have taught you valuable lessons by not giving you everything you want. You'll know how to look for bargains and save money, but she won't. You'll understand that you need to work hard to get the things that you want but she won't. When Tiffany is a grown woman, she'll wake up one day and she will be wishing that she had a mom like the one you've got. Life lessons are more important than modern clothes and delicious food."

    It took some time, but I eventually understood my mom's words. Now I am a happy and successful woman.