Our body clock, or natural body rhythm, influences our energy and alertness. Paying attention to it can help us choose the suitable time of the day when we best perform specific tasks.

    The reality, however, is that most of us organize the time around work demands, school deadlines, commuting or social events. Doing whatever the body feels like doing is a luxury in today's fast-paced modern society.

    But that doesn't mean it isn't worth trying. Obeying our body clock has significant health benefits. Disrupting our natural body rhythm, on the other hand, has been linked to problems such as depression, obesity, or headache, says Steve Key, a biology professor.

    When the body clock can synchronize (使…同步) the rhythms of its natural processes, it “gives us an advantage in daily life”, says Key.

    According to him, when it comes to cognitive (认知的) work, most adults perform best in the late morning. As our body temperature starts to rise just before awakening in the morning and continues to increase until midday, our memory, alertness and concentration gradually improve.

    However, he adds, our ability to concentrate typically starts to decrease soon thereafter. Most of us are more easily distracted (分心) between noon and 4 pm.

    Alertness also tends to fall after eating a meal and sleepiness tends to peak around 2 pm, making that a good time for a nap.

    Surprisingly, tiredness may increase our creative powers. For most adults, problems that require open-ended thinking are often best dealt with in the evening when they are tired, according to a study in the journal Thinking & Reasoning.

    When choosing a time of the day to exercise, paying attention to your body clock can improve results. Physical performance is usually best from about 3 to 6 pm, says Michael Smolensky, a professor of biomedical engineering.

    Of course, not everyone's body clock is the same, making it even harder to synchronize natural rhythms with daily plans.

    Going green seems to be fad(时尚)for a lot of people these days. Whether that is good or bad, we can't really say, but for the two of us, going green is not a fad but a lifestyle.

    On April 22,2011,we decided to be green every single day for an entire year. This meant doing 365 different things, and it also meant challenging ourselves to go green beyond the easy things. Rather than recycle and reduce our energy, we had to think of 365 different things to do and this was no easy task.

    With the idea of going green every single day a year, Our Green Year started. My wife and I decided to educate people about how they could go green in their lives and hoped we could show people all green things that could be done to help the environment. We wanted to push the message that every little bit helps.

    Over the course of Our Green Year, we completely changed our lifestyles. We now shop at organic(有机的) stores. We consume less meat, choosing green food. We have greatly reduced our buying we don't need. We have given away half of what we owned through websites. Our home is kept clean by vinegar and lemon juice, with no chemical cleaners. We make our own butter, enjoying the smell of home-made fresh bread. In our home office anyone caught doing something ungreen might be punished.

    Our minds have been changed by Our Green Year. We are grateful for the chance to have been able to go green and educate others. We believe that we do have the power to change things and help our planets.

    Why do so many tourists come to Easter Island? Because it has world-famous stone statues (雕像) . These statues, whose likenesses look like humans with huge stone cylinders（柱状物）balancing on their heads like hats, have tourists coming from all over the world. The tourists come to see these works of ancient art carved by the early inhabitants of the island. They come to see the mystery that has puzzled historians for decades.

    Easter Island is located in a remote part Of the South Pacific Ocean about 2,300 miles west of Chile. Easter Island covers just 45 square miles and its Polynesian name is Rapa Nui.

    On Easter Sunday 1722, a Dutch explorer named Jacob Roggeveen was the first European to see Easter Island. The early Polynesians carved the statues within the holes of the volcano (火山) using only stone tools. Then they moved these huge statues to various destinations throughout the island. These 600 statues range in height from 10 to 40 feet. Some of them weigh as much as 50 tons. How could the early Polynesians lift hundreds of heavy statues out of the volcano? How did they move them across the island to their various locations? All of these questions, as well as many others, remain unanswered.

    The early islanders probably worshiped (崇拜) these eyeless giants until sometime around 1670. In 1680, a war broke out between two groups of islanders. The victors（胜利者）of the war and ancestors of the present inhabitants, broke down many of the statues. In most cases, they broke the necks of the statues.

    Now 15 of the statues on Easter Island have been repaired to their original positions on their stone platforms. Even today, using modern tools and machinery, putting up such large statues and balancing cylinders on top of their heads presents a challenging task.

    Hiking England

    DAY 1: ST. BEES TO ENNERDALE BRIDGE

    Our journey sets out early this morning with a Coast to Coast tradition approaching the Irish Sea. Then set off along the rocks of St. Bees Head. Turning inland, we'll pause for a typical pub lunch on our way to Ennerdale Bridge, located at the foot of the Lake District mountains. (15 miles hiking, 8 hours)

    Accommodations: Ennerdale Country House Hotel

    DAY2: ENNERDALE BRIDGE TO HONISTER

    Today we'll walk into impressive Lake District National Park, where glass-like lakes reflect mountains that rise from their shores. Our pleasant walk covers the southern edge of Ennerdale Water, the park's most western lake. After lunch near the Black Sail Hut, climb a 2,000 foot mountain and take in the beautiful views of lakes and pastures (牧场). We finish in Borrowdale, a short transfer (转乘) from our hotel. (13 miles hiking, 9 hours)

    Accommodations: Inn on the Lake

    DAY 3: GRASMERE TO GLENRIDDLNG

    Take a short drive to Grasmere, where the great poet William Wordsworth wrote some of his most well-known works. Visit the poet's home, and walk through the village where he found inspiration. Then climb over Grisedale Hause enjoying views of Helvellyn, England's third-highest mountaintop. Hike down the valley toward Lake Ullswater and spend the night in Glenridding. (9 miles hiking, 5 hours)

    Accommodations: Glenridding Lake Hotel

    DAY 4: LAKE ULLSWATER TO SHAP

    The day begins with a scenic journey on Lake Ullswater to Howtown. From here, we cross a historic Roman road on our way to Bampton. Hike to the 12th-century Shap Abbey. A short transfer takes us to our hotel in the typical English village of Ravenstonedale. (12 miles hiking, 7 hours)

    Accommodations: The Black Swan

    Throughout history scientists have risked their health and their lives in their search for the truth.

    Sir Isaac Newton, the seventeenth century scientist, was very smart, but that didn't stop him from doing some pretty stupid things. In his laboratory in Cambridge he often did the strangest experiments. Once, while testing how light passes through lenses (晶状体), he put a long needle into his eye, pushed it to the back, and then moved it around just to see what would happen. Luckily, nothing long-lasting did. On another occasion he stared at the sun for as long as he could bear, to discover what effect this would have on his sight. Again he escaped suffering permanent damage, though he had to spend some days in a darkened room before his eyes recovered.

    In the 1750s the Swedish chemist Karl Scheele was the first person to find a way to produce phosphorus (磷). He in fact discovered eight more chemical elements including chlorine (氯), though he didn't get any praise for them. He was a very clever scientist, but his one failing was a curious habit of tasting a little of every substance he worked with. This risky practice finally caught up with him, and in 1786 he was found dead in his laboratory surrounded by a large number of dangerous chemicals, any of which might have been responsible for his death.

    Eugene Shoemaker was a respected geologist. He spent a large part of his life studying craters (火山口) on the moon, and how they were formed, and later did research into the comets of the planet Jupiter. In 1997 he and his wife were in the Australian desert where they went every year to search for places where comets might have hit the earth. While driving in the Tanami desert, normally one of the emptiest places in the world, another vehicle crashed into them and Shoemaker was killed on the spot. Some of his ashes (骨灰) were sent to the moon aboard the Lunar Prospector spacecraft and left there — he is the only person who has had this honor.

My First Day of School

    Fear started taking over, I was walking into my first school in America. I had traveled a long distance from India in order to join my parents, who had been for three years, hoping America would help my future. My father decided that I would be better off going to school here, so I enrolled(登记)in the local high school in my new town.

    I was afraid how I would do. On the first day, I went to my second period class after I had missed my first. With anxiety, I reached for the door, opening it slowly. Without paying attention to my classmates, I went straight to the teacher and asked if this was the right class. With a soft voice he answered. "Yes." His voice comforted me a little. He gave me a sheet called Course Requirements, which I would never get in India because we didn't have anything like that. Then he asked me to choose where I would sit. I didn't actually want to pick a seat. In India we had fixed seats, so I never needed to worry about that. I spent the rest of the class taking notes from the image produced by the overhead projector. In Indian schools, we didn't use the technology we had. We had to take notes as the teacher spoke.

    It was noon. I was very confused about when I would have lunch. I went to my next class and the bell rang as I entered. I went through the regular process of asking the teacher if I was in the right class. She said, "It's still fourth period."

    "But the bell just rang," I said.

    Changing from a gentle tone to a harsher(刺耳的)one, she said, "That is the lunch bell, young man."

    I apologized. Without another word I headed for the cafeteria. I felt lucky because we didn't have this in India. Every confusion seemed like a barrier I had to get through to reach my goal. At the end of the day, I was on my way to the bus which we didn't have in India either. I spotted my bus and sat down inside happily. I was thinking, today wasn't so bad.