If you've ever owned a chimney, you know that it can get pretty dirty. There's a whole lot of soot(烟灰) that gets stuck on the inside. That stuff has to get cleaned, or you could have a serious fire risk. While nowadays we have easier ways of doing this dirty job, in the way back days somebody used to climb up the chimney and clean all that soot. And the thing is, not just anybody could do it.

    You had to be really small to fit up in the chimney, so they used to give the task to kids – some as young as four or five years old. They worked for their boss known as a master-sweep. They were often covered in soot, and were very likely to get burned. They often developed what became known as soot wart, a form of cancer.

    Are your unfairness bells ringing? William Blake's certainly were. The physical dangers and widespread unfairness of the chimney-sweeping job really stuck in his throat, so much so that he wrote not one, but two poems called “The Chimney Sweeper”.

    The first poem (the one we're discussing here)was published in 1789 in a book called Songs of Innocence. These little poems took children and the joys of childhood innocence as their subject. As you've probably guessed by now, many of the poems in Songs of Innocence, like “The Chimney Sweeper”, are about the ways in which childhood innocence is destroyed by unkind old adults. For Blake, innocence is, in many ways, a total joke. It doesn't exist, because it's always taken away by the realistic world – chimney-sweeping, death, poverty, etc.

    What does a five-year-old chimney sweeper in 18th-century England have to do with you? More than you might think. It is reported that 150 million kids are in child labor in developing countries. Many of them work long hours and face dangerous health risks. Like Blake's chimney sweeper, these kids are not even given a chance at innocence because experience keeps getting in the way.

    Teachers say the digital age has had a good influence and a not-so-good influence on this generation of American teenagers. More than 2,000 high school teachers took an online survey.

    75 percent of the teachers said the Internet and digital search tools have had a “mostly positive” effect on  their students' research habits and skills. But 87 percent agreed that these technologies "make the students not have enough attention.” And 64 percent said the technologies “do more to distract students than to help them academically.”Many students think “doing research” now means just doing a quick search on Google.

    Judy Buchanan is a director of the National Writing Project. Ms. Buchanan says digital research tools are helping students learn more, and learn faster. Teachers really like these tools, because they are ways to make some of learning exciting. Young people enjoy using these tools. And the goal is to help them become creative students of meaningful work, and not just that kind of copyist.

    But one problem the survey found is that many students don't have a good understanding of how to use the digital knowledge well. In other words, they trust(信任) too much of the information. Judy Buchanan says these students have not developed the skills they need to tell whether the online information is good or bad.

    Another problem the survey found is something that might not seem like a problem, at all, being able to quickly find information online. Teachers say the ability of their students to work hard to find answers is becoming weaker. They say students depend too much on search engines (引擎) and do not make enough use of printed books or research, librarians.

    Besides, many teachers are also worried about the problem that the Internet makes it easy for students to copy work done by others, instead of using their own abilities.

    While beach vacations may be a great way to take your mind off work，lakes surrounded by mountains make for an even grander experience．If you are looking for some peace on your vacation，we have some recommendations for you in the Caucasus(高加索)．

Lake Sevan

    Lake Sevan is situated in the central part of Armenia，in the Gegharkunik province．It is the largest lake in Armenia，located 6,200ft above sea level．Along the lake shore，there are various accommodations such as resorts and hotels with plenty of activities to partake in such as windsurfing，swimming and sunbathing．While there，do not forget to visit one of the famous cultural monuments，the Sevanavank Monastery，and it offers a great view of the lake as well．

Lake Paravani

    Lake Paravani，located at 6,801ft above sea level，is in the south of Georgia，near the Javakheti plateau．At this level，altitude sickness can occur and it is a good idea to be prepared to adapt to it properly，or bring medication for altitude sickness．Being a volcanic lake makes for a more interesting experience．The lake is best known for fishing．Do not come home during the winter months when the lake freezes．

Lake Cildir

    Lake Cildir is located in the Ardahan province，East Turkey，near the borders of Georgia and Armenia．It is the second largest freshwater lake of Eastern Turkey，and many tourists are not aware of this beautiful attraction．Lake Cildir is surrounded by mountains of the Caucasus．The lake freezes during late November．If the winter is not extremely cold，you can try some lake activities like ice skating and ice fishing．

Lake Van

    Lake Van is the must visit of all lakes in this list．The largest lake in Turkey，Lake Van is located on the eastern shore of Turkey and is also the most accessible lake here．It's situated at 5，380ft above sea level，and unique to lakes around the world，the water is high in salt content．

    Olympic National Park, with its temperate rainforests and breath-taking views, exerts a natural pull on many Pacific Northwestemers. But Seattle writer Rosette Royale found it repellent. To Royale, the park seemed like a damp, dirty and unpleasant place. "I couldn't figure out why anyone would want to carry a 50-pound pack into the wilderness and camp there for days," he said. "It didn't make sense."

    Then he met Bryant Carlin, a vendor (小贩) for Real Change, the Seattle weekly sold on the street by vendors who are homeless or low-wage earners. He was also a skilled outdoorsman and a nature photographer who would take weeks-long photographic journeys to the park. The two men connected in the fall of 2011 when Royale interviewed Carlin for a feature story in Real Change about Carlin's photography.

    That first time they met—and for years afterward—Carlin invited Royale to go camping with him. Each time, Royale said "Thanks, but no thanks." Until one day, in the spring of 2015, Royale surprised himself by saying yes. "Little did I know," said Royale, "that saying 'yes' would change the course of my life."

    Royale and Carlin went on five separate journeys to the Olympic wilderness. They camped in spring, summer, fall and winter. For Royale, the trips were exhausting and terrifying. But the trips were also inspiring, and helped Royale—a black, strange man—to develop a relationship with the outdoors that he had never experienced before.

    For Carlin, the trips were an opportunity to throw off the label of "homeless". In Olympic National Park, sleeping outside just means you're a camper. But there was one aspect of Carlin's life in the city that he couldn't escape: alcohol abuse. While he never brought beer on their camping journeys, the effects of years of drinking weren't so easy to leave behind.

For Adam Johnson, a potter from Brighton, the interest stirs (萌动) each spring. "It grabs a hold of me," he said. "I just get the desire to dig." Together with his shovel (铲), he is part of a larger movement. Around the world people are discovering the joys of an ancient practice: the digging of holes. TikTok videos of people digging purely for fun have been viewed millions of times. Instagram accounts devoted to the pastime have many followings.

Charlie Mone, a student at St Andrews University, was changed while digging on the beach in Gran Canaria last year. When he returned home, he founded the university's first hole-digging society. "I didn't think it would go anywhere," he said. Dozens of diggers regularly attend its events on East Sands Beach on the east coast of Scotland and the society's Facebook page has more than 300 followers.

Mone believes that that much of the appeal lies in the friendship working on a shared project in the sea air. "It's struck a chord (共鸣) with people," he said. "There's something therapeutic to just switching your brain off and digging a hole." At the end of each 1 session, the holes are filled in to prevent accidents.

Back in Brighton, Johnson, 38, is more of a lonely digger. "I have often started digging without an actual plan," he said. "Once I took out an unruly bramble (荆棘) and found some rock so I dug that out, then carried on a bit until I was in a good general digging rhythm. A few hours later my partner asked if I was coming in for dinner-the bramble had come out at breakfast and I found myself in a six-foot hole. The hole would become a sunken hot tub, but the digging would have been worthwhile anyway, he suggests. "There's something basic about it. And you find all kinds of buried treasure from people who had the garden before you. There's something magical about digging."

In 1999, John Smith, a high-school teacher decided it was time to retire. Together with his wife Helen, he set off on a journey around Australia. But when they returned, John found he missed the classroom, so he spent another eight years doing casual teaching.

Then he heard about a program known as Volunteers for Isolated Students' Education (VISE), which pairs up energetic people with educational experience, usually retired teachers, with children whose schooling is largely done remotely, because they live too far away from towns and cities to attend regular schools. John grew up in the country and as a kid in the bush, he always dreamed of running with circus, but he didn't even have much chance to see the circus in person. Therefore he was immediately interested in the program and got a travelling post as a teacher with Stardust Circus.

The lesson timetable was built around the kid's performance schedules. "The eight-year-old I tutored was an awesome gymnast who was part of the teeterboard(跷跷板) act," he explains. "A big guy would jump on the other side, he would swing up in the air, do a couple of twirls(旋转) and land on his uncle's shoulders, and his uncle was standing on the boy's father's shoulders!"

The circus still includes some animal acts, including lions, monkeys, horses, goats and pigs. John and his wife Helen found it extraordinary enough to sink into sleep to the sound of lions roaring, but one day the lion-trainer, Matt, gave him a very special privilege,inviting him in to meet four 13-month old lions in person. While it was understandably a little scary at first, for John it was a never-to-be-forgotten experience, which helped him realize his boyhood dream in ms 75th year.