Houses fall down. Trees fall over. Large holes form in the ground. Could Alaska be sinking? That's what some villagers in Alaska have been asking themselves recently and scientists think they know why. Warmer temperatures may be causing Alaska's frozen ground to thaw (解冻).

    About 85 percent of Alaska's land surface has permafrost (永久冻结带). Permafrost supports the ground above it—including trees, houses, and roads. But why is the permafrost thawing?

    Some scientists say that human-caused pollution is leading to global warming. And most scientists agree that Alaska has been getting warmer. They say that the warmer temperature is causing permafrost to thaw in some areas. The thawing permafrost can cause problems for people, plants, and animals.

    The collapsing (倒塌) is a problem in the villages in Alaska which are built on permafrost, and some of them may have to move to safer ground, where there is no permafrost.

    The Alaskan town of Glennallen saw its old post office collapse. And, according to James Walters, a permafrost expert at the University of Northern Iowa, house-moving companies have been very busy.

    “Melting permafrost can also destroy trees and forests,” Walters said. “When holes in the ground form, trees fall into them and die. This could turn a forest into a swamp (沼泽), and animals which need the forests will have to move elsewhere.”

    “The melting could cause severe problems.” Walters says, “This could take hundreds of years, but in the end Alaska will look quite different from what it looks like now.”

    Ireland has had a very difficult history. The problems started in the 16th century when English rulers tried to conquer (征服) Ireland. For hundreds of years, the Irish people fought against the English. Finally, in 1921, the British government was forced to give independence to the south of Ireland. The result is that today there are two "Irelands". Northern Ireland, in the north, is part of the United Kingdom. The Republic of Ireland, in the south, is an independent country.

    In the 1840s, the main crop, potatoes, was affected by disease and about 750,000 people died of hunger. This, and a shortage (短缺) of work, forced many people to leave Ireland and live in the USA, the UK, Australia and Canada. As a result of these problems, the population fell from 8.2 million in 1841 to 6.6 million in 1851.

    For many years, the majority of Irish people earned their living as farmers. Today, many people still work on the land but more and more people are moving to the cities to work in factories and offices. Life in the cities is very different from life in the countryside, where things move at a quieter and slower pace.

    The Irish are famous for being warm-hearted and friendly. Oscar Wilde, a famous Irish writer, once said that the Irish were “the greatest talkers since the Greeks”. Since independence, Ireland has revived (复兴) its own culture of music, language, literature and singing. Different areas have different styles of old Irish songs which are sung without instruments. Other kinds of Irish music use many different instruments such as the violin, whistles, etc.

    Aunt Karen always had a special place in my heart. When I was growing up, I knew I could count on her to have room for me on her lap and words of love and encouragement when I needed to hear them. When she died five years ago, I was devastated. The whole family was still in shock when her husband, Uncle Ronnie, died a week later. I longed to have a small item of Aunt Karen's to remember her by, but seeing her children and grandchildren overcome by the grief of this double loss made me shy away from asking.

    A few months after Aunt Karen's death, I was on my way to work when I saw Rescued Treasures, a local second-hand store. I only had a couple of dollars on me and didn't really intend to buy anything, but I stopped anyway just to look inside. I had been shopping around for a few minutes when a small, black handbag caught my eye. It wasn't fancy or special. I didn't really need a handbag and continued to look around the store, but something kept drawing me back to that handbag. Finally, I checked the price tag (标签). It was just one dollar.

    The handbag stayed in the back of my car for weeks until I came upon it during a car clean-up. I opened it up. I couldn't believe it. They hadn't even cleaned it out. It was still full of junk, old candy wrappers, old receipts (收据) and used paper. Usually the store emptied things inside, so there wouldn't be any surprises for a new owner.

    I threw away some wastes, and sorted through the receipts, when I found one item in the small inside pocket. It was an insurance card with the name “Karen Stair” written on it. I began to cry. My beloved Aunt Karen. This was her handbag.

    If you want to slow aging, you might want to eat less. This finding is good news—if you were a mouse. The researchers studied mice, not people.

    John Price and other researchers studied two groups of mice. One group was able to eat as much as it wanted. The researchers limited what the mice in the other group ate. Their diet had 35 percent fewer calories than the first group of mice.

    Price says the mice with the diet restrictions were “more energetic and suffered fewer diseases.” They were not just living longer but seemed to stay younger for a longer period of time.

    The researchers found that fewer calories slow down a natural mechanism in cells called ribosomes. Price explains that ribosomes are responsible for making important proteins in the cells. But with fewer calories, they slow down. This gives the cells more time to repair themselves.

    The researchers say ribosomes use from 10 to 20 percent of the cell's energy to make those proteins. Price wrote that “because of this, it is impractical to destroy an entire ribosome” when it starts to break down. However, “repairing individual parts of the ribosome on a regular basis enables ribosomes to continue producing high quality proteins for longer than they would otherwise. This top quality production, in turn, keeps cells and the entire body functioning well.”

    Price said, “ribosome is a very complex machine, like a car.” They need “maintenance to replace the parts that wear out the fastest. When tires wear out,” he explained, “you don't throw the whole car away and buy a new one. It costs less to replace the old tires.”

    “Food,” he said, “isn't just material to be burned—it's a signal that tells our body and cells how to respond.” Price said the findings help to explain how exactly our bodies age. And this may “help us make more educated decisions about what we eat.”

    I have been unusually silent these past ten months. I had thought that silence would soon be coming to an end,, but I'm afraid I must tell you now that fate（命运）has decided on a different course for me.

    In August of last year, I underwent surgery to remove a cancerous tumor in my abdomen. That operation was thought to have been a success, but it caused a series of secondary complications – which I have been fighting in hospital ever since. It was along and hard fight with many setbacks, but I was steadily, if slowly, overcoming each obstacle along the way and gradually making my way back to health.

    However, recent tests have revealed that the cancer has returned. There was no sign or it as recently as a month ago, which means it is aggressive and spreading rapidly. My doctors tell me their best estimate is that I have only a few weeks left to live. This is the final conclusion. My fight is over.

    I wish to thank my doctors and caregivers, who efforts have been magnificent. My dear friends, who have given me a lifetime of memories and whose support has sustained me through these difficult months. And all of my partners at The Washington Post, Fox News, and Crown Publishing.

    Lastly, I thank my colleagues, my readers, and my viewers, who have made my career possible and given consequence to my life's work. I believe that the pursuit of truth and right ideas through honest debate and thorough argument is a noble undertaking. I am grateful to have played a small role in the conversations that have helped guide this extraordinary nation's destiny.

    I leave this life with no regret. It was a wonderful life – full and complete with the great loves and great endeavors that make it worth living. I am sad to leave, but I leave with the knowledge that I lived the life that I intended.

    Do you have any foreign friends? Do you know their characteristics(特征)?

    The Germans are very quiet and they always keep calm. They don't like to speak many words. They look very serious. They like different kinds of amusements. The Germans are very hard-working. They like tidiness, especially the women, who always keep their home clean.

    In some ways, the Englishmen look the same as the Germans. They are very quiet and never talk too much with the strangers. They are really polite, so we often hear they say “Thank you.” or “Sorry.” The gentlemen are also the Englishmen.

The French's holidays are very long. They like traveling and usually spend their long time on staying in other countries. The Frenchmen are more outgoing than the Germans. It is very easy to make friends with them.

    Compared to the Frenchmen, the Americans are more outgoing. And they are even opener than all of the Europeans. They don't like to depend on others. So it is very common that the students do part-time jobs in their free time. And in Americans' eyes, success is an important part in their life.