Many of us remember being in awe(敬畏) when we saw cloned dinosaurs running wild in the film Jurassic Park. And the idea of using technology to revive(恢复) extinct species has long fascinated not only writers and directors, but scientists as well.

    According to The Telegraph, woolly mammoths(长毛猛犸象), which featured in the popular Ice Age animated movie series, “may walk the earth once more” now that scientists have taken another step toward realizing a long-held dream—recreating their DNA.

    Mammoths became extinct around 10,000 years ago. However, since the discovery of near-perfect preserved remains in Arctic permafrost(北极冻土带) in May 2013, a variety of research studies have been carried out since.

    Geneticists from Harvard University analyzed DNA from the remains, looking for genes which separated mammoths from elephants, such as hairiness and ear size. They then used the results to reproduce exact copies of 14 mammoth genes. “It is the first time that mammoth genes have been alive—although so far it has only been done in the lab,” George Church, lead researcher of the project, told the Sunday Times.

    Church then used a new technique which allows scientists to edit DNA carefully, replacing sections of elephant DNA with the mammoth genes. So “we now have functioning elephant cells with mammoth DNA in them,” he said.

    However, Church ruled out the possibility of bringing the mammoths back to life via cloning from frozen remains. He said he “preferred to focus on rebuilding the full mammoth genome(基因组) by analyzing DNA from preserved remains and putting it into the cells of its closest living relative – the Asian elephant,” reported The Telegraph.

    Church argued that the return of the woolly mammoth—or rather, the return of something very similar—could help bring back fragile(脆弱的) ecosystems. However, some scientists believe that bringing back the mammoth would be unethical.

    Professor Alex Greenwood, an expert on ancient DNA, said: “We may face the extinction of African and Asian elephants. Why bring back another elephant from extinction when we cannot even keep the ones that are not extinct around?” he told the Sunday Times. “What is the message? We can be as irresponsible with the environment as we want. Then we'll just clone things back?”

    “Money would be better spent focusing on conserving what we do have than spending it on an animal that has been extinct for thousands of years,” he said.

    The Healthy Habits Survey（调查）shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.

1). How many times did you brush your teeth yesterday?

Finding：A full 33% of seniors brush their teeth only once a day.

Step：Remove the 300 types of bacteria in your mouth each morning with a battery-operated toothbrush. Brush gently for 2 minutes, at least twice a day.

2). How many times did you wash your hands or bathe yesterday?

Finding：Seniors, on average, bathe fewer than 3 days a week. And nearly 30%wash their hands only 4 times a day-half of the number doctors recommend.

Step：We touch our faces around 3, 000 times a day-often inviting germs（病菌）to enter our mouth, nose, and eyes. Use toilet paper to avoid touching the door handle. And, most important, wash your hands often with hot running water and soap for 20 seconds.

3). How often do you think about fighting germs?

Finding：Seniors are not fighting germs as well as they should.

Step：Be aware of germs. Do you know it is not your toilet but your kitchen sponge（海绵）that can carry more germs than anything else? To kill these germs, keep your sponge in the microwave for 10 seconds.

    Once when I was facing a decision that involved high risk, I went to a friend. He looked at me for a moment, and then wrote a sentence containing the best advice I've ever had: Be bold and brave — and mighty (强大的) forces will come to your aid.

    Those words made me see clearly that when I had fallen short in the past, it was seldom because I had tried and failed. It was usually because I had let fear of failure stop me from trying at all. On the other hand, whenever I had plunged into deep water, forced by courage or circumstance, I had always been able to swim until I got my feet on the ground again.

    Boldness means a decision to bite off more than you can eat. And there is nothing mysterious about the mighty forces. They are potential powers we possess: energy, skill, sound judgment, creative ideas — even physical strength greater than most of us realize.

    Admittedly, those mighty forces are spiritual ones. But they are more important than physical ones. A college classmate of mine, Tim, was an excellent football player, even though he weighed much less than the average player. “In one game I suddenly found myself confronting a huge player, who had nothing but me between him and our goal line,” said Tim. “I was so frightened that I closed my eyes and desperately threw myself at that guy like a bullet（子弹） — and stopped him cold.”

    Boldness — a willingness to extend yourself to the extreme—is not one that can be acquired overnight. But it can be taught to children and developed in adults. Confidence builds up. Surely, there will be setbacks (挫折) and disappointments in life; boldness in itself is no guarantee of success. But the person who tries to do something and fails is a lot better off than the person who tries to do nothing and succeeds.

    So, always try to live a little bit beyond your abilities—and you'll find your abilities are greater than you ever dreamed.

    Balancing work and school is not an easy task for me. My first term in college has come and gone and I've had to balance a job there, too. I want to cut one loose. Honestly, many times I thought I wanted to drop out of school and just do my job because I needed the money. For a long while I made myself believe that school was getting in the way of my job and money. Not only was I trying to do work and school, but also I was trying to have a social life. Many times I thought that there were not enough hours in the day but I wasn't managing my time right. Hanging out with friends may have been wonderful but it wasn't putting money in my pocket or knowledge in my brain. Friends would have to wait. I was back on the see-saw (跷跷板) of balancing work and school.

    Scheduling and planning became the key to my success. Setting deadlines and meeting them were important to my college experience. Planning was going well and I felt ready to try and throw a social life back there. I tried to make plans with friends that didn't conflict with my deadlines. That was actually harder than I thought. So once again my social life had to be put on hold (搁置). My friends were very understanding and encouraged me to do my work. The extra motivation really proved helpful in the end. Some friends would joke that I was all work and no play but sometimes that's what has to happen to get work done.

    As the last term came to an end I can say I learned a lot about college life. Planning is necessary for organization. Drawing up a list of all things I had to do at the beginning of the week and actually completing them made me feel good. Not only have I learned something new about organization, but also I acquired a new tool that I can take everywhere with me and use effectively.

Hot Air Balloons

    The basis of how the balloon works is that warmer air rises in cooler air. This is because hot air is lighter than cool air as it has less mass per unit of volume. Mass can be defined by the measure of how much matter something contains. The actual balloon has to be large as it takes a large amount of heated air to lift it off the ground.

    The burner uses propane gas to heat up the air in the envelope to move the balloon off the ground and into the air. The pilot must keep firing the burner at regular intervals throughout the flight to ensure that the balloon continues to the stable. Naturally, the hot air will not escape from the hot at the very bottom of the envelop as firstly, hot air rises and secondly, the floating power keeps it moving up.

    To move the balloon upwards, the pilot opens up the propane value which lets the propane flow to the burner which in turn frees the flame up into the envelope. It works in much the same way as a gas grill: the more you open the valve, the bigger the flame to beat the air and the faster the balloon rises.

    The “Parachute Valve” at the very top of the balloon is what is used to bring the balloon down towards the ground. It is a circle of fabric cut out of the top of the envelop which is controlled by a rope which runs down through the middle of the envelope to the basket. If the pilot wants to bring the balloon down, he or she simply pulls on the rope which will open the valve, letting hot air escape, decreasing the inner air temperature. This cooling of air causes the balloon to slow its rise.

    The pilot can operate horizontally by changing the vertical position of the balloon because the wind blows in different directions at different altitudes. If the pilot wants to move in a particular direction, he or she simply arises and falls to the appropriate level and rides with the wind.

    Choosing where to live may be one of the biggest decisions you'll make when you move to Sydney, but you'll have plenty of help.

    Temporary arrival accommodation

    Before you move to Sydney, we recommend that you book a temporary place to stay. Once you get here, you can look for longer-term accommodation.

    --sydney.edu.au/accommodation/short-term

    On-campus-residential colleges (fully catered饮食全包的)

    The University has eight residential colleges on the Camperdown/Darlington Campus, including International House, a residential community of global scholars. Colleges provide comfortable, fully furnished single rooms and daily meals, along with sporting, cultural, leadership and social programs. They also include on-site tutorials(辅导课) in addition to campus-based classes.

    --sydney.edu.au/colleges

    On-campus residences (self-catered饮食自理的)

    The University has two self-run residences ­ Queen Mary Building (QMB) and Abercrombie Student Accommodation ­ on the Camperdown/Darlington Campus. Both just under a year old, they house up to 1000 students. These residences provide modern single-study rooms with large common living, learning and study spaces, shared kitchens, a theatre, gyms, soundproofed music rooms, art studios, sky lounges and rooftop gardens.

    --sydney.edu.au/campus-life/accommodation/live-on-campus.html

    Off-campus living

    More than 90 percent of our students live off campus. The University is close to many dynamic and multicultural suburbs such as Annandale, Newtown, Chippendale and Glebe. A great place to search is our large online database of properties.

    --sydney.edu.au/campus-life/accommodation/live-off-campus.html