Phil White has just returned from an 18,000 ­mile, around­ the ­world bicycle trip. White had two reasons for making this epic journey. First of all, he wanted to use the trip to raise money for charity, which he did. He raised ￡70,000 for the British charity, Oxfam. White's second reason for making the trip was to break the world record and become the fastest person to cycle around the world. He is still waiting to find out if he has broken the record or not.

    White set off from Trafalgar Square, in London, on 19th June 2004 and was back 299 days later. He spent more than 1,300 hours in the saddle (车座) and destroyed four sets of tyres and three bike chains. He had the adventure of his life crossing Europe, the Middle East, India, Asia, Australia, New Zealand and the Americas. Amazingly, he did all of this with absolutely no support team. No jeep carrying food, water and medicine. No doctor. Nothing! Just a bike and a very, very long road.

    The journey was lonely and desperate at times. He also had to fight his way across deserts, through jungles and over mountains. He cycled through heavy rains and temperatures of up to 45 degrees, all to help people in need. There were other dangers along the road. In Iran, he was chased by armed robbers and was lucky to escape with his life and the little money he had. The worst thing that happened to him was having to cycle into a headwind on a road that crosses the south of Australia. For 1,000 kilometres he battled against the wind that was constantly pushing him. This part of the trip was slow, hard work and depressing, but he made it in the end. Now Mr. White is back and intends to write a book about his adventures.

    According to a team of researchers, an animal's ability to perceive(感知) time is linked to their pace of life.

    “Our results lend support to the importance of time perception in animals where the ability to perceive time in a very short time may be the difference between life and death for fast moving creatures.” commented lead author Kevin Healy from Trinity College Dublin.

    The study was done with a variety of animals using phenomenon based on the maximum speed of flashes of light an individual can see before the light source is seen as constant. Dogs, for example, have eyes with a refresh rate higher than humans.

    One example of this phenomenon at work, the authors say, is the housefly and its ability to avoid being hit. The research showed flies “observe motion in a shorter time than our own eyes can achieve,” which allows them to avoid being hit.

    Professor Graeme Ruxton of the University of St Andrews in Scotland, who worked jointly on the research project, said in a statement, “Having eyes that send updates to the brain at much higher frequencies than our eyes do is of no Value if the brain cannot process that information equally quickly. Thus, this work highlights the impressive abilities of even the smallest animal brains. Flies might now be deep thinkers, but they can make good decisions very quickly.”

    In comparison, the tiger beetle (虎甲虫) runs faster than its eyes can keep up, basically becoming blind, which requires it to stop periodically to re-evaluate its prey's(猎物) position.

    Our results suggest that time perception offers an as yet unstudied dimension along which animals can specialize and there is considerable range to study this system in more detail.

    Today, I had the good fortune to join the students from East Silver Spring Elementary School in Maryland as they walked and biked to school in celebration of International Walk to School Day. I want to thank Principal Morrow and the entire ESS community for welcoming me so enthusiastically.

    Walk to School Day is a great opportunity for me to spend time with parents, kids, and teachers and to present our Safe Routes to School program and the First Lady Michelle Obama's Let's Move initiative（倡议）.

    As a father, grandfather and former schoolteacher, I know how important it is that we provide students with safe choice to get to school while promoting exercise and healthy lifestyles. That's why I've embraced the Safe Routes to School program so wholeheartedly since I became Secretary of Transportation.

    You know, we're looking at an increasingly sedentary（久坐的）generation of children. One out of every three kids in America is now overweight. And I admire the First Lady's effort to end this within a generation. Safe Routes to School is a natural partner for Let's Move. For more than 10 years, Safe Routes to School has been making it easier for students to walk and bike from home to school. And ESS, where I walked today, is one of the earliest schools to participate.

    We know this program has been enormously effective because of the steady increase in the number of kids walking or biking to school. And as we made our way down the street this morning I was reminded yet again of this program's extraordinary work.

    Look, walking and biking to school is good for students' health. It's good for the environment. And it's good for the entire community's quality of life.

Everybody wins when kids take Safe Routes to School.

    For World Heritage(遗产) Sites, you probably think of places connected with ancient art and culture, and historical buildings. But there are a few of the more unusual sites.

    Citadel of Haiti.

    These monuments were built at the end of the nineteenth century when Haiti became independent and the many thousands of black slaves in Haiti were free for the first time. These ex-slaves built the monuments, which The World Heritage List (WHL) describes as a true symbol of liberty.

    The Darjeeling Himalayan Railway in India.

    This railway was opened in 1881 and is still operating today. It crosses a difficult area of mountain landscape and it is a great example of railway engineering. The WHL says that it is the first and still the most outstanding example of a hill passenger railway.

    Borders of France and Spain.

    This is an area of great natural beauty and the mountains have many interesting geological shapes. Besides, people there still use a type of agriculture that used to be common in mountainous areas of Europe but has almost completely disappeared in modern times. The WHL says it shows us about past European society through its landscape of villages, fields and mountain roads.

    Alto Douro, Portugal.

    This is an area in the North of Portugal where wine has been produced for thousands of years. Nowadays it is world-famous for the port wine that is produced there. The WHL says that this long tradition of wine making has produced a cultural landscape of outstanding beauty that reflects its technological, social and economic development little by little.

    Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures（核心体温）in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity（湿度）.

In very cold climates, there is a constant danger of developing hypothermia（低体温）, which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0℃. However, differences in persons and even the time of day can cause it to be as much as 6℃ higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4℃. Below 29.4℃, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6℃. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7℃.

In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7℃. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.

My love for libraries blossomed when I joined the public library. From the age of 8 I was allowed to walk from my home to the downtown library, housed above the police station. Once the librarian gave me my first membership card, I could enjoy a range of books, which started with Little House in the Big Woods. I was addicted instantly, and this love of libraries and reading would change my life, allowing me to one day create a safe space for high-school kids, too.

By the time I was in high school, I could read the authors that we were studying in class, including Charles Dickens, Mark Twain and Emily Bronte. During the summer months, I got caught up in Gone with the Wind.

When I studied English literature at university, I thought it was time to build my own library. For the next 40 years, I continued to collect books. Until one day, I realized that all my books had become a part of the house, like wallpaper.

Toward the end of my teaching career, I became a teacher-librarian at my old high school, where I had first learned English literature. This position enabled me to regain my love and appreciation for libraries. I had a generous budget for my classes, so I searched for novels that would interest my teenage audience and hopefully spark a love of books. Fantasy, science-fiction, graphic novels -I bought almost any type of books that my students wanted to read. I bought sofas and comfortable chairs, turning the library into a safe public space, for everyone.

In doing so, I realized that the library isn't just a place to do research. They are, in fact, places that offer an opportunity to connect with the past, present and future. All that is required is a tiny bit of curiosity. Libraries are places that should be full of life. They help us adjust to the world, and their doors must be kept open to everyone for free!