Why do human beings still risk their lives under ground and doing one of the dirtiest and most dangerous jobs in the world? It is an increasingly urgent question, given the recent mining accidents in Sago, W. Va and Huntington, Utah. A small group of engineers and robotics experts look forward to a day in the not-too-distant future when robots and other technology do most of the dangerous mining work.

    Robotic technology, in particular, holds much promise, McAteer says, especially when it comes to mapping mines and rescuing trapped miners — the special operations of the mining industry.

    One of the first mining robots was developed five years ago at Carnegie Mellon University's Robotics Institute. It was called Groundhog. It used lasers(激光器) to “see” in dark tunnels and map abandoned mines—some of the most dangerous work in the business.

    The latest design is called Cave Crawler. It's a bit smaller than Groundhog, and even more advanced. It can take photos and videos and has more sensors that can detect the presence of dangerous gases. Incredibly, the robot has a real sense of logic. If it comes across an obstacle it gets momentarily confused. It has to think about what to do and where to go next. Sometimes it throws a fit just like a real person.

    The greatest problem, though, is cost. The money of the earliest research project was provided by the government, but that money had dried up, and it's not clear where future money will come from. Partly for that reason, and partly because of advances in safety, mining is not nearly as dangerous as it was in the past. Since 1990, fatalities(致命性) have declined by 67% and injuries by 51% , according to the National Mining Association.

    Some experts predict that robots in mines will serve much of the same function that they do in the automotive industry. The robots do the most boring and dangerous jobs，but won't get rid of the need for human workers.

    What would work be like if you had no boss?Imagine you could make all your own decisions and no one told you what to do.

    A Swedish software company,Crisp,decided to get rid of their CEO.First,they needed to find out what a CEO actually did.Then they shared those duties among staff and board members,which is exactly what they did.And the employees believes it's been a good change.An employee named Heinrik Kniberg says the company can now act faster,"If you want to get something done,you stand up and start driving that.Workers are also more active and satisfied."And any big decisions are made during the all-member meetings several times a year.

    So,if it's working well for Crisp,could this model become more widespread? Online retailer（零售商）Zappos tried out a similar plan but had unpleasant results.Almost a fifth of its staff decided to leave,and CEO Tony Hsieh admitted that "self-management is not for everyone".Mr Houston,founder of file-sharing service Drew Dropbox,says that total freedom doesn't always feel good,because you no longer know what you're supposed to do,what is important and you're bumping up against other people."

    Would you like to work somewhere with no boss?

    Sharon, Aged 22

    The most important thing to keep in mind when going into high school is to be yourself. Besides, I don't know what your middle school was like, but high school teachers will not care about things such as how much homework you already have in one night. It's best to just learn to deal with things and manage your time wisely so you can achieve everything you need to.

    Frank, Aged 21

    I think almost every kid feels both nervous and excited before their first day. You will probably love it. I know I did. You should join in some sports or activities that will make your high school experience more enjoyable. Good luck!

    David, Aged 19

    I'm not going to lie. The first day is kind of frightening. But you'll get used to it. Don't be afraid of anyone; upperclassmen will pick on you more if you let them know you're afraid. Just take it easy. Making some friends and staying with them will greatly help you get used to high school quickly. After the first week it's really not bad at all. Don't worry.

    Eddie, Aged 20

    When I started high school I was really nervous too, especially since I had been homeschooled all through middle school and didn't really know anyone. I suppose the best advice would be to just relax. The first couple of days can be a little bit hard, but things will become easier before you know it.

    To be sure, only children experienced some things differently from those with sisters and brothers. Many feel more pressure to succeed. They also tend to look only to their parents as role models in the absence of brothers and sisters.

    In India, 10-year-old Saviraj Sankpal founded a support group for the tiny minority(少数) of only children. Among other things, the group does volunteer work to fight against the false idea that they are not responsible. "People think we're treated too kindly and ruined," says Sankpal, a computer engineering student. "But I'd like to remind them how lonely it can get."

    Most only children, however, say they wish for sisters or brothers only when it comes to caring for aging, unhealthy parents. Britain's David Emerson, co-author of the book The Only Child, says that such a person has to make all the decisions alone. Emerson knows from experience. After his father died, he chose to move his elderly mother from their family home, where she was vulnerable (易受攻击的) to house breakers, to a new one with more safety. "The move was quite hard on her, and she might feel that I pushed her into it, "he says, "After all, I am left with that responsibility."

    In the future, more and more only children will probably face similar choices. With working mothers increasing, many families are finding they simply don't have the time, money or energy to have more than one child. As only children become common, perhaps the world will realize that the charge made against them is unfair.

Save the Animals

    Animals are natural resources(资源）that people have wasted all through our history.

    Animals have been killed for their fur and feathers(羽毛), for food, for sport, and simply because they were in the way. Thousands of kinds of animals have disappeared from the earth forever. Hundreds more are on the danger list today. About 170 kinds in the United States alone are considered in danger.

    Why should people care? Because we need animals. And because once they are gone, there will never be any more. Animals are more than just beautiful or interesting. They are more than just a source of food. Every animal has its place in the balance(平衡)of nature. Destroying one kind of animal can create many problems.

    For example, when farmers killed large numbers of hawks(鹰), the farmers stores of com and rain were destroyed by rats and mic. Why? Because of hawks ate rats and mice that multiplied(繁殖)quickly

    Luckily, some people are working to help save the animals. Some groups raise money to let people know about the problem .And they try to get the governments to pass laws protecting animals in danger.

    Quite a few countries have passed laws. These laws forbid(禁止)the killing of any animals or plants on the danger list. Slowly, the number of some animals in danger is growing

    A retired United States soldier named Terry McGlade, who had served in Iraq and Afghanistan, his dog Major is a hero. He is specially trained to says sense when McGlade is about to have a seizure, get his phone and dial 911 for help.

    When Major had recently sensed an incident about to happen, and McGlade collapsed and hit the floor, Major was able to get to McGlade's phone, and more or less bite on the phone which is specially set up so that when multiple buttons are pressed and held in, it goes into emergency call mode, and dial 911.

    "He was actually able to get my phone out of my pocket," McGlade said.

    The 911 operators who got the call from Major said they never heard him bark or anything. However, they could hear what sounded like a confused man in the background, and did get quite suspicious after quite a few calls from McGlade's cell phone kept coming in. Quite clearly, Major was using his leg and also stepping on the screen to get the phone to díal for help.

    After Major was sure someone would be on their way to help, he then made his way out to the front of the house to wait. When police and ambulance arrived, he led them into the house and right to McGlade, still in distress.

    "I probably would have been in severe trouble if he wouldn't have called," McGlade said.

    McGlade was taken to the hospital, where he was kept overnight for observation, but thanks to his best friend, and now hero of the day, Major. He is feeling much better, and will make a full recovery with little risk of lasting damage from this particular incident.