【推荐1】Nearly two decades ago when the Google Books Project digitized and freely distributed more than 25 million works, book publishers argued that free digital distribution weakens the market for physical books. However, new research from Imke Reimers and Abhishek Nagaraj reveals that the opposite — increased demand for physical books, through online discovery — could be true.

The two researchers focused on a particular part of Google Books’ digitized works: those from Harvard University’s Widener Library, which helped seed the project in its early days. The condition that enabled their experiment: Harvard’s digitization effort only included out-of-copyright works, published before 1923 , which were made available to consumers in their entirety. The works from 1923 and later were still copyrighted and not digitized.

The researchers analyzed a total of 37,743 books scanned (扫描) between 2005 and2009. They looked at sales for the two years before this digitization period and the two years after , and found clear differences in the increased sales between digitized and non-digitized books. Approximately 40% of digitized titles saw a sales increase from 2003-2004 to 2010-2011, compared to less than 20% of titles that were not digitized. The increase in sales was also found to be stronger for less popular books.

“If a book is readily available online, people may decide that it’s a useful book and want to buy it,” Reimers said. “The ‘discovery effect’, which even increased the sales of a digitized author’s non-digitized works, is a strong driver of increased sales. It’s not a huge jump in sales , but it’s still good news for publishers.”

“And book lovers,” Reimers said, “are known for their preference for physical books, as opposed to digital versions, which could also play a role.” She added ,“Whenever I talk to people about my research on books, at some point they all say,’ I just love the feel of a digitized author’s non-digitized works, is a strong driver of increased sales. It’s not a huge jump in sales , but it’s still good news for publishers.”

“And book lovers,” Reimers said, “are known for their preference for physical books , as opposed to digital versions, which could also play a role.” She added, “Whenever I talk to people about my research on books, at some point they all say, ‘I just love the feel of a book in my hand.’”

【推荐1】To be a good teacher, you need some of the gifts of a good actor; you must be able to hold the attention and interest of your audience; you must be a clear speaker, with a good, strong, pleasing voice which is fully under your control; and you must be able to act what you are teaching, in order to make its meaning clear.

Watch a good teacher, and you will see that he does not sit still before his class:he stands the whole time he is teaching; he walks about, using his arms, hands and fingers to help him in his explanations, and his face to express feelings. Listen to him, and you will hear the loudness, the quality and the musical note of his voice always changing according to what he is talking about.

The fact that a good teacher has some of the gifts of a good actor doesn’t mean that he will indeed be able to act well on the stage, for there are very important differences between the teacher’s work and the actor’s. The actor has to speak words which he has learnt by heart; he has to repeat exactly the same words each time he plays a certain part, even his movements and the ways in which he uses his voice are usually fixed beforehand. What he has to do is to make all these carefully learnt words and actions seem natural on the stage.

A good teacher works in quite a different way. His audience takes an active part in his play：they ask and answer questions, they obey orders, and if they don’t understand something, they say so. The teacher therefore has to meet the needs of his audience, which is his class. He cannot learn his part by heart, but must invent it as he goes along.

I have known many teachers who were fine actors in class but were unable to take part in a stage-play because they could not keep strictly to what another had written.

【推荐3】Even though people have been disabled playing sports like rugby and football, extreme sports take the whole ordeal (磨难) to the next level. Sports like downhill cycling are very dangerous because one would be going downhill, over rocky or dirt zones, through forests, even at potentially deadly speeds. A slip-up could be your downfall.

Nobody who gets into extreme sports goes with the desire to do harm to themselves. With that, athletes train for years and years before they attempt anything extreme. To most people, extreme sports are extreme simply because they take more skill than what an average person has. An athlete with skill and training makes an extreme thing become a daily routine, which does not wipe out the danger, but greatly reduces it.

Even when there is a lot of skill involved, things might not go the athlete’s way, not at all. Luck and circumstances have a lot to do with how things develop, whether above 8, 000 meters or in a wood, going downhill. In some places, crossing the street is an extreme sport, considering how wild traffic can get.

Some view parkour, the sports of running, jumping and climbing under, around and through buildings, as an extreme sport, while it is more of a life philosophy, where the athlete does not have to do anything remotely dangerous. Free soloing, which means climbing a rock or ice face without safety gear, is absolutely deadly, where one slip means almost certain death, depending on the height, of course. Skateboarding is relatively safe, but if you constantly find ridiculous places to practice on, like the fence of a bridge, then things can get very complicated. The extreme part depends on the athlete.

To summarize, yes, extreme sports are dangerous, but the danger depends on the athlete, their choice of sport, direction in which they take it, as well as the circumstances. Some things are out of our control, while others we can influence through exercise and healthier risk choices.