A biologist from the National Park Service discovered a rare and unusual mammoth(猛犸) skull(颅骨) buried in a 13,000-year-old rock layer on the Santa Rosa Island, the second largest landmass in the Channel Islands, California. The fossil of the extinct giant animal is leaving many paleontologists(古生物学家) scratching their heads. Despite the fact that it's possibly the best preserved mammoth skull ever found and of high scientific importance, the species of the individual it belonged to can't seem to be identified yet—it's too big to be a pygmy(特别矮小的) mammoth and too small to have come from a Columbian mammoth. Some say it's a new species while others believe the truth lies somewhere in between.

    The first mammoths showed up in North America around two million years ago, but it was only during the last two ice ages that the Columbian species, which could grow to be up to 14 feet tall, made its way to the Channel Islands 100 miles west of Los Angeles. Once the ice melted, many populations became trapped on the island and evolved into pygmy mammoths, an endemic species(地方种) to the Channel Islands which grew only to six feet tall.

    Judging from its size, the newly found mammoth skull doesn't seem to fit any of the two species, Columbian or pygmy. To make things even more confusing, one of its two tusks(象牙) is nearly five feet long and coiled in a manner that resembles those of fully grown mammoths but the left tusk is shorter and sloped, more like a juvenile(青少年).

    This has caused some scientists to say the Santa Rose skull may belong to a transitional species. Whatever's the case, a following examination of the mammoth's teeth should put the matter to rest. The analysis will also tell us how old the mammoth was when it died, so we can tell for sure whether it was an adult or juvenile.

    More interesting than the mammoth's lineage, however, might be its story. The giant mammal lived 13,000 years ago or roughly the same timeline of the “Arlington Man”, a 13,000-year-old human skeleton also found on Santa Rosa. Some 3,000 years later humans were already spread throughout the continent and the Channel Islands' mammoth went extinct. The present finding might help reveal a link between the two.

    The remains also seem to confirm a long-held assumption that there were two mammoth migrations to the Channel Islands. “The discovery of this mammoth skull increases the probability that there were at least two migrations of Columbian mammoths to the island: during the most recent ice age 10,000 to 30,000 years ago, as well as the previous ice age that occurred about 150,000 years ago,” said USGS geologist Dan Muhs.

    The morning had been a disaster. My tooth was aching, and I'd been in an argument with a friend. Her words still hurt: “The trouble with you is that you won't put yourself in my place. Can't you see things from my point of view?” I shook my head stubbornly—and felt the ache in my tooth. I'd thought I could hold out till my dentist came back from holiday, but the pain was really unbearable. I started calling the dentists in the phone book, but no one could see me immediately. Finally, at about lunchtime, I got lucky.

    “If you come by right now,” the receptionist said, “the dentist will fit you in.”

    I took my purse and keys and rushed to my car. But suddenly I began to doubt about the dentist. What kind of dentist would be so eager to treat someone at such short time? Why wasn't he as busy as the others?

    In the dentist's office, I sat down and looked around. I saw nothing but the bare walls and I became even more worried. The assistant noticed my nervousness and placed her warm hand over my ice-cold one.

    When I told her my fears, she laughed and said, “Don't worry. The dentist is very good.”

    “How long do I have to wait for him?” I asked impatiently.

    “Come on, he is coming. Just lie down and relax. And enjoy the artwork,” the assistant said.

    “The artwork?” I was puzzled.

    The chair went back, suddenly I smiled. There was a beautiful picture, right where I could enjoy it: on the ceiling. How considerate the dentist was! At that moment, I began to understand what my friend meant by her words.

    What a relief！

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    One of Scotland's most active centenarians ( 百岁的人), Lady Morton, drove for nearly 80 years. She loved driving and spent the war years as an ambulance driver for Bangour Hospital. Aged 100 she was still driving around Edinburgh, up to Perthshire and elsewhere — the oldest among all the drivers in Scotland. But she had her first ever accident several days after her 100th birthday — she hit a traffic island (a raised area in the middle of a road where people can wait until it is safe to cross) when she took her new car for a drive in Edinburgh.

    Lady Morton, who celebrated her 100^th birthday in July, was given a car as a present. She talked about the accident happened that night. “I wasn't going fast, but I hit a traffic island. I couldn't see it, because it had no light, which I think was unbelievable and unreasonable. But I am all right and luckily my car wasn't badly damaged.

    Although Lady Morton had the accident, she didn't plan to stop driving.“Some people are just born to drive, and I think I am one of them. I've been a good driver since the first time I got in a car, she said. “I am musical, so I listen to sound of the car to know when to change gear (档位).

    Lady Morton bought her first car in 1927. The main change she had noticed since then is the traffic. “It's appalling. However, I don't mind it, because I am experienced, but I feel very sorry for beginners,” she said.

    In the United States, when one becomes rich, he wants people to know it. And even if he does not become very rich, he wants people to think that he is. That is what "keeping up with the Joneses" is about. It is the story of someone who tried to look as rich as his neighbors.

    The expression was first used in 1913 by a young American called Arthur Momand. He told this story about himself. He began earning $ 125 a week at the age of 23. That was a lot of money in those days. He got married and moved with his wife to a very wealthy neighborhood. When he saw that rich people rode horses, Momand went horseback riding every day. When he saw that rich people had servants. Momand and his wife also hired a servant and gave big parties for their new neighbors.

    It was like a race, but one could never finish this race because one was always trying to keep up. The race ended for Momand and his wife when they could no longer pay for their new way of life. They had to move back to an apartment in New York City. Momand looked around him and noticed that many people do things just to keep up with rich lifestyle of their neighbors. He saw the funny side of it and started to write a series of short stories. He called it "Keeping up with the Joneses" because "Jones" is a very common name in the United States. "Keeping up with the Joneses" came to mean keeping up with rich lifestyle of the people around you. Momand's series appeared in different newspapers across the country for over 28 years.

    People never seem to get tired of keeping up with the Joneses. And there are "Joneses" in every city of the world. But one must get tired of trying to keep up with the Joneses because no matter what one does, Mr. Jones always seems to be ahead.

Learning to Run

    An article published in the scientific journal Nature discusses an important aspect of human evolution. According to Bramble and Lieberman, Professors at the University of Utah, humans possess a number of features that make them surprisingly good runners. “We are confident that the selection for running was important in the origin of the human body form,” says Bramble.

    Traditional thinking has been that humans are poor runners compared to such animals as horses. However, this is only true if we consider running at high speed, especially over short distances. Even an athlete can hardly run as quickly as a horse does, and can only keep up a top speed for 15 seconds or so. But when it comes to long-distance running, humans will do astonishingly well. They can keep a steady pace for many kilometres, and their speed is at least at the same level with that of horses.

    Bramble and Lieberman examined 26 parts of human bodies. One of the most interesting of these is the nuchal ligament (韧带). When we run, it is this ligament that prevents our head from moving back and forth or from side to side. Therefore, we are able to run with steady heads, held high. Then there are Achilles tendons at the backs of our legs, forming the mechanical links between the muscles to the bones. They act like strong strings and help to push us forward when we run. Besides, we have low, wide shoulders, a development which allows us to run more effectively. Add to this our light forearms, which swing in co-operation with the movement of our legs to assist balance, and one begins to appreciate the point that Bramble and Lieberman are trying to make.

    But what advantage is gained from being good long-distance runners? One theory is that this ability may have permitted early humans to obtain food more effectively. Some scientists guess that early humans may have run after animals for great distances to make them tired before killing them. Running would also have shown another advantage: early humans might have eaten the meat left over from a kill by other large animals. They may have been warned of the existence of a freshly killed animal by vultures (秃鹰), and the faster they got to the scene of the kill, the better.

    “Research on the history of human ability of running has traditionally been controversial,” says Lieberman. “At the very least, I hope this theory will make many people have second thoughts about how humans learned to run and why we are built the way we are.”

    When to go: The Magic Kingdom, which was opened in 1971, was the first theme park at Walt Disney World. All Disney World theme parks are opened 365 days a year, although opening and closing time for each park changes from day to day. If you plan to make a trip to the Magic Kingdom without kids, try to visit on a school day to avoid the largest crowds. If you need to visit during a school vacation, try at least to avoid the week between Christmas and New Year's Day and the fourth of July.

    If you are not staying at a Disney World hotel, avoid visiting the Magic Kingdom on its Extra Magic Hours days, as Disney's hotel guests get into the park early on those days, and visitors who arrive at the Magic Kingdom's normal opening time have to wait for a long time.

    Before you go：Buy your Walt Disney World tickets online at Disney World's website. For advice on picking the right ticket, see our guide to Disney World tickets.

    You will also need to call in advance to make lunch or dinner reservations. Disney accepts reservations(预订)up to 180 days in advance, but you need to contact 1-407-WDW-DINE.

    When you get there: Plan to arrive at the Magic Kingdom's front gate before the park opens in the morning. Keep in mind that to reach the Magic Kingdom, you must park at Disney World's Transportation and Ticket Centre parking lot, ride a tram (有轨电车)to the TTC, then take a ferry boat across the Seven Seas Lagoon to the Magic Kingdom. It makes a fantastic approach, but takes extra time. Give yourself an extra hour in the summer and half an hour during the school year.