One afternoon last week, I saw three tearful children from my son's school being comforted by teachers. That morning, my 11-year-old had stomach pains, retching(干呕)into a bowl. Talking to other mothers later, I heard about other children with stomachache or difficulty sleeping the night before.

What caused so much pain? Sports day. Sports day might be necessary at a highly-competitive independent school, but not at a village primary school. For the children who can fly like the wind, sports day causes no problem. For those who are overweight or just not good at sport, it is a nightmare(噩梦). Even for those who enjoy running but fall halfway down the track in front of the entire school and their parents, it can prove a disaster.

    Why do we put our children through this annual suffering? Some may say competition is character building; or it's taking part, not winning, that's important; or that it is a tradition of school life. I just felt great pity for those children in tears or in pain.

    Team games at the end of sports day produced some close races, wild enthusiasm, lots of shouting—and were fun to watch. More importantly, the children who were not so fast or quick at passing the ball were hidden a little from everyone's eyes. Some of them also had the thrill of being on the winning side.

    I wish that sports day could be abandoned and replaced with some other less-competitive event. Perhaps an afternoon of team games, with a few races for those who want them, would be less stressful for the children and a lot more fun to watch.

    If you are studying at school, do be a polite and clever student! There is no excuse for not doing your assignments. If you can't come to school, you should call your teacher or your classmate ask about homework. It is your responsibility to find out what homework you have missed. It is not the teacher's job to remind you of the missed assignments.

    You must not be absent on a test day. If you are seriously ill, call and let the teacher know you will not be there for the test. If your teacher allows a make-up test, you should take the test, again within one or two days after you return to class. Serious illness is the only reason for missing a test.

    Be on time! It is impolite to be late. Also, it bothers other students. If you must come in late, be sure to do it quietly. Have your books and papers out of your bag before you come into the classroom. Then go to your seat and sit down quietly. In the USA, it is not necessary to knock before you enter the classroom. Most teachers will give you a low grade if you are often late.

    In America, you should call your teacher by his or her last name instead of “teacher”. Also you should use Mr, Miss, Ms or Mrs before the last name (such as Mrs Smith or Mr Jones). The teacher will tell you the title that he or she likes. It is impolite in the USA to eat, drink or chew gum during class. Don't do these until the break. Also, removing your shoes in the classroom is not polite.

    In America, each of the states likes to promote itself with a slogan (口号). I currently live in Utah, where the slogan is '“Life Elevated”. It's a nod to outdoor entertainment in the hill country, including the ski industry. I previously lived in Colorado, a land with red dm. great mountains and golden plains. The slogan there is ''Colorful Colorado”. Years ago I lived in the “Peach State” of Georgia, and I grew up in New Mexico as a little boy, whose slogan is “Land of Enchantment (魔力)”.

    We never seemed to get away from dust in New Mexico, so I appreciate the story of a newcomer to the Land of Enchantment who learned about dusty wind. She was visiting an antique shop and the owner wiped down every item before showing it. The newcomer said, “Everything gets dusty here pretty quickly, doesn't it?” “That's not dust, honey,” the shop owner replied, “That's ENCIIANTMENT”. That made the problem more acceptable or at least can be live with. An escalator (自动扶梯) broke, so he posted a sign to warn customers. He chose not to use the traditional “Out of Order” or “Do Not Use” warnings. Instead, his sign read, “This Escalator Is Temporarily a Stairway”. He turned a minus into humor and made it a plus.

    And in fact there arc sonic things, like the weather, we can't change. All we can change is our ways that we think and feel about them. I believe one of the best techniques to do this is to find some humor in the situation. Finding something amusing or enjoyable of difficulty, a troublesome problem can be one of the most creative and effective things we can do. Sometimes the only sense you can make of a situation is a sense of humor.

    How a few members of the animal kingdom handle the transition to adulthood?

    African elephants

These beautiful beasts come close to imitate teen rebellion. Calves spend a decade with their mothers in female-dominated groups —- and ladies stay there —- but adolescent boys leave mom for noisy crews of bros. In their 20s, they often downsize to smaller male groups.

    Orangutans (猩猩)

Slow metabolism allows these primates to survive food shortages —- times when weather makes ripe fruit scarce. But energy efficiency comes at a cost; growth and maturation take time. Orangutan mamas nurse their young longer than any other wild creature does.

    Orcas(逆戟鲸)

    Killer whales join their mother's familial group for life. This lasting-relationship seems to increase a pup's chance of survival; if mom dies  a young male (under 30) is three times more likely to die than a peer whose mother is alive. Risk of death post-mom-mortem rises as kids get older.

Harp seals

A harp seal's "childhood" lasts just 12 days. A pup's sole purpose during that brief period of coddling(宠爱) is to constantly nurse, gaining a fifth of its birth weight in blubber(鲸脂) every day. Once it's fat —- they become greater from 25 to 80 pounds —- it slides off the ice and takes on the sea.

    Wolf spiders

    Every parent knows that tired toddlers love to hitch a piggyback ride. The wolf spider straps all her babies (40 or 50, on average) onto her back at once, carrying the brood until they are capable of fully functional spider-hood. But luckily she only has to pull them for a few days.

    Time zone:

    Eastern Standard Time(EST): GMT+10 hours.

    There is no daylight saving time in Queensland.

    Legal drinking age:

    18 years and older. Always keep your ID with you to prove your age.

    Alcohol(酒) shops & hotels are the only places where alcohol can be bought.

    Dangers:

    Dial 000 from a fixed line or 112 from a mobile phone. Police, ambulance, fire.

    Electricity:

    240/250 volts AC 50Hz Universal outlets for 110 volts (shavers only) standard in hotels, apartments, motels.

    Telephones:

    Australian international code is 61.

    Road rules:

    Left hand side driving. There is a 50kmh speed limit in most living areas and on open highways100-110kmh. Seat belts must be worn all the time. If you want to hire a car, take along your driver's license.

    No smoking:

    Indoors: Indoor areas are no smoking.

    Poker Machines: Poker machine areas are no smoking.

    Outdoors: Non-enclosed eating and drinking areas are no smoking.

Swimming Safety:

    ALWAYS SWIM BETWEEN THE RED AND YELLOW FLAGS and pay attention to the life guards' advice. Gold Coast beaches are guarded by skilled life guards and volunteers at weekends.

A living robot has been created out of frog skin cells. Xenobots, named after the frog species Xenopus laevis that the cells come from, were first described last year. Now the team behind the robots has improved their design and demonstrated new capabilities.

To create the xenobots, Michael Levin at Tufts University in Massachusetts and his colleagues obtained tissue from 24-hour-old frog embryos after very small physical operation. Where the previous version relied on the contraction of heart muscle cells to move them forward by pushing off surfaces, these new xenobots swim around faster. They also live between three and seven days longer than their previous generation, which only lasted about seven days, and have the ability to sense their surroundings to some extent, turning red when exposed to blue light.

"The fundamental finding here is that when you free skin cells from their normal context, and you give them a chance to build other things than what they normally build," says Levin. "To me, one of the most exciting things here is that they are plastic. This idea that even normal cells, not genetically modified, are in fact capable of building something completely different."

Because they are created from cells, the xenobots eventually break apart and are totally biodegradable, says team member Douglas Blackiston, also at Tufts University. He therefore hopes that they can be used for biomedical and environmental applications.

Previous attempts at creating living robots, such as a wirelessly controlled cockroach, have involved dealing with live animals, raising ethical concerns. Xenobots differ from these because they are made entirely of living cells. "The approach here is maybe ethically the least problematic because everything starts with cells. They have no neurons, so it's not an animal," says Auke ljspeert at the Swiss Federal Institute of Technology at Lausanne, who wasn't involved in the research. "It's really cells, so I find it maybe the cleanest way."