Dr. Sasaki knew the first-night effect probably has something to do with how humans evolved.

    The puzzle was what benefit would be gained from it when performance might be affected the following day. She also knew from previous work conducted on birds and dolphins that these animals put half of their brains to sleep at a time so that they can rest while remaining alert enough to avoid predators (捕食者). This led her to wonder if people might be doing the same thing. To take a closer look, her team studied 35 healthy people as they slept in the unfamiliar environment of the university's Department of Psychological Sciences. The participants each slept in the department for two nights and were carefully monitored with techniques that looked at the activity of their brains. Dr. Sasaki found, as expected, the participants slept less well on their first night than they did on their second, taking more than twice as long to fall asleep and sleeping less overall. During deep sleep, the participants' brains behaved in a similar manner seen in birds and dolphins. On the first night only, the left hemispheres (半球) of their brains did not sleep nearly as deeply as their right hemispheres did.

    Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps (蜂鸣声) of the same tone and irregular beeps of a different tone during the night. She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones. This is precisely what she found.

    James Cook, at the age of forty, was sent by England to explore the Pacific Ocean. On his third voyage, as captain in charge of two ships, the Discovery and the Revolution, he came upon a group of unknown islands which he named the Sandwich Islands after his friend, the Earl (伯爵) of Sandwich. Today the islands are known at the Hawaiian Islands.

    When Cook sailed into a protected bay (海湾) of one of the larger islands, the natives greeted him with curiosity and respect. Some historians said that the islanders welcomed him, believing he was the god, protector of peace and agriculture.

    The islanders were short, strong people with a very well-organized social system. The men fished and raised crops. The women prepared for the children and made clothing for the men and short skirts for the women.

    Every summer, my family and I visit our relatives in India and whenever we travel, my parents always remind me to drink only bottled or boiled water. On one of my trips to India, I saw children drinking water from the roadside. I was troubled to learn that millions of people, most of them children in developing countries, die each year because of water related diseases.

    Living in the US, I am lucky to be able to turn on the tap and get potable water(饮用水), while one sixth of the world's population lacks access to clean water This year, I entered the Discovery Education 3M Young Scientist Challenge. In late June, I learned that I was selected as one of the top 10 national finalists of this famous middle school science competition. Over the summer, I worked with Dr. Jim Jonza, my Scientist mentor(导师 )from 3M, and developed a system that uses solar energy to purify water. My invention is green and cost effective, and I am looking forward to implementing this in places that are affected(影响)by harmful water pollution.

    In October, my family and I flew to 3M Headquarters in St Paul, Minnesota, where the final event was to be held. For the last challenge, each of us had to present the invention we had been working on over the summer. The first place winner would win $25,000, a trip to Costa Rica, and the title of America' Top Young Scientist. At the awards ceremony, all of us waited anxiously until one of the judges, Danny Forester, started announcing "The winner of the Discovery Education 3M Young Scientist Challenge is…" You could hear a pin(大头针) drop as he opened the paper with the winner' s name, "Deepika Kurup!"

    As America's Top Young Scientist, I was given an opportunity to show my invention on national television and deliver several presentations. One of the most important things I have learned is that communication and teamwork are key to success.

    "Let's go see Santa!" Samantha said, pointing.

    I shrugged. I found out long ago that the real Santa doesn't hang out in malls. He's always too busy checking his list for kids twice and supervising the elves (小精灵).

    Last year, "Santa" had a tattoo on his arm. I pretended I didn't notice and named all the toys I ever wanted, until he was about to kick me out. I like playing around with fake Santas.

    We joined the line and after what seemed like ages, it was our turn. Samantha's eyes were glowing with excitement as she listed her wishes. She went back to Mom and Dad with a delighted smile and some candies.

    I sat on Santa's lap and moved from side to side to get comfortable. He made a face. "Have you been good this year? Ho! Ho!"

    "Oh, yes! I played nicely with my sister, obeyed my parents, and teachers are fond of me. "

    A suspicious smile appeared on his jolly face. "What would you like for Christmas, my boy?" "Santa, I want a new teacher for Christmas."

    He got a little surprised and looked at me. "Don't you want any new games, or a baseball mitt (手套)?"

    "No. I want a new teacher who doesn't give too much homework. I don't have time to play anyway, with all those assignments I'm getting. "

    It was worth waiting in line just to see the look on his face. He gave me a coloring book and a Christmas sticker. Just before I left, he pulled me closer and said in a low tone, "I'll make sure Miss Coleman makes your wish come true."

    How did he … that voice … "Mr. Principal?"

    I guess sometimes wishes do come true. I had a lighter workload until June!

A healthy lifestyle includes many choices. Among them, choosing a balanced diet or healthy eating plan is of the greatest importance. But how do you choose a healthy eating plan? Let's begin by explaining what a healthy eating plan is.

A healthy eating plan that helps you manage your weight includes different kinds of foods you may not have considered. If "healthy eating" makes you think about the foods you can't have, try refocusing on all the new foods you can eat.

Fresh, Frozen, or Canned Fruits -- don't think about just apples or bananas. All fresh, frozen, or canned fruits are great choices. Be sure to try some fruits from other countries, too. How about a mango, a juicy pineapple or kiwi fruit? What you should pay attention to about canned fruits is that they may contain added sugars. You'd better choose canned fruits packed in water or in their own juice.

Fresh, Frozen, or Canned Vegetables – try something new. Don't eat the same kinds of vegetables all the time. You can try to eat different kinds of vegetables, which is important for a good diet. When trying canned vegetables, look for vegetables without added salt or butter. You can go to the produce department(果蔬部) and try a new vegetable each week.

Calcium(钙)-rich foods -- you may firstly think of a glass of low-fat or fat-free milk when someone says "Eat more dairy products " But what about low-fat and fat-free yogurts without added sugars? There is a wide variety of flavors and they can be a great dessert instead of those with a sweet tooth.

What's more, you don't need to give up your favorite comfort food. You can enjoy your favorite foods even if they are high in calories, fat or added sugars. The key is eating them only once in a while, and balancing them out with healthier foods and more physical activity.

The point is that you can figure out how to include almost any food in your healthy eating plan in a way that still helps you lose weight or maintain a healthy weight.

Five years ago, I left my job to work on a ship. After working as a junior doctor, I was willing to take the risk.1 for adventure, I boarded a ship in Singapore with 2, 000 passengers and crew. To my2 , the hospital was well equipped, with an X﹣ray machine and a blood analyzer.

As a doctor, I was3 for the 600 crew. Far from4 seasickness and sunburn, I had to deal with other diseases. The ship's medical centre was5 a floating emergency room, and we didn't have a team of specialists on hand for a second6 . With long and unpredictable hours, it required mental7 .

Many of the passengers were elderly. Heart attacks don't8 geography and emergency evacuations （疏散）were difficult to arrange. I recall one such patient, who was taken off the ship halfway through the Panama Canal. After a9 ride in an old ambulance, I was relieved that the patient10 long enough to arrive at the hospital in Panama City.11 , there were several unexpected benefits to the job. I regularly12 the passenger facilities. On rare days off, I13 as a tour guide on trips ashore.

Now, I understand being a ship doctor is not a job﹣it's a way of14 . One year at sea became two. I lost my career ambitions,15 I redefined happiness in my life.