A machine that takes sweat-laden (浸满汗水的) clothes and turns the sweat into drinking water is in use in Sweden. The machine makes the clothes turn round quickly, heats them to remove the sweat, and then passes the steam through a kind of special material to make purified water.

    Since it has been brought into use, its creators say more than 1000 people have drunk others' “sweat” in Gothenburg. They add the liquid is cleaner than local tap water.

    The device was built for the United Nations' child-focused charity UNICEF to promote a campaign highlighting the fact that 780 million people in the world lack access to clean water.

    The machine was designed and built by the engineer Andreas Hammar, known locally for his appearances on TV tech show “Mekatronik”. He said the key part of the sweat machine was a new water purification part developed by a company named HVR.

    “It uses a technique called membrane distillation (膜蒸馏),” he told the BBC. “We use a special kind of material that only lets steam through but keeps bacteria, salts, clothing fibers and other things out. They have something similar to the International Space Station, but our machine is cheaper to build. The amount of water it produces depends on how sweaty the person is, but one person's T-shirt typically produces 10ml, about a mouthful.”

    The device has been put on show at the Gothia Cup-the world's largest international youth football tournament. Mattias Ronge, chief executive of Stockholm-based advertising agency Deportivo, said the machine had helped raise awareness for UNICEF, but in reality had its limitations.

    “People haven't produced as much sweat as we hoped – right now the weather in Gothenburg is lousy,” Mattias Ronge said. “So we've equipped the machine with exercise bikes and volunteers are cycling like crazy. Even so, the demand for sweat is greater than the supply. And the machine will never be produced in large numbers, since there are better solutions out there such as water purifying pills.”

    Tulou, the special residential architecture of Fujian Province was included on the UNESCO's World Heritage List during the 32nd session of the World Heritage Committee in Quebec, Canada.

    In the fourth century, Han Chinese living in the Central Plains area began to migrate south, gradually gathering in Fujian and forming the Hakka communities. As a defence against enemies, the Hakkas chose to live in compact (紧凑的) communities, and the tulou was their preferred houses. Tens of thousands of such earthen structures were constructed in Fujian Province.

    Most tulous are to be found in the valleys, surrounded by high mountains, and some are in the depths of the great mountains. Most are three to four storeys high, and look like circular blockhouses (堡垒). Rooms on the first floor are used as kitchens, rooms on the second floor are used as barns (谷仓), and rooms on the third and fourth floors are for bedrooms and living rooms. For defensive purposes, the rooms on the first floor have no windows.

    Raw materials for the tulou were obtained locally. Their main building material was a mixture of clay, sand, lime and water, and egg whites, brown sugar and rice water were added as adhesive agents (粘合剂). It was then mixed to form the walls. Once they dried, the walls were so hard that driving a nail into them would have been difficult. Fir branches, which are extremely strong and do not rot, were used to strengthen them, and many centuries later they have remained their original look.

    Tulous are located in a region where earthquakes happen frequently, and their circular construction helps them resist the regular shocks.

    The proven design even inspired one famous Peruvian architect, who paid several visits to Yongding, to build a tulou back home. Not long after, an earthquake struck only 10 kilometers away, and while all the houses around the earthen building fell down, his tulou remained.

    I remember my childhood summers fondly, as many of us do. Those golden days in which I would leave the house after a still sleepy, leisurely breakfast and come home only for lunch in the middle of a day spent entirely outdoors. We did not live in town and, thus, playmates were limited to siblings (兄弟姐妹) and the cousins who lived down the road.

    Our backyard became the playground in which our imaginations would run wild—turning those few acres into magical forests, the creek (小溪) into a violent river and our trusty dog, Rex, into the many roles of horse, monster and any other creature that we children did not want to play. By the end of the three months of summer break we were sunburned from our hours in the sun, full of the memories of a thousand magical moments and bonded to our siblings in a way that winter's forced hibernation (冬眠) never seemed to connect us.

    Today, I live on the same acreage that I did as a child. My children have the blessing of having the same grassy patches to scratch their bare feet as they run through it, the same creek to stomp(跺脚)through, and not the same dog—but their very own energetic pup to imagine away the days with.

    However, this is not the same world as it was twenty, thirty years ago. There are screens everywhere in the house to demand attention—televisions with hundreds of channels, computers with access to a thousand entertaining sites, tablets stocked with apps. There is also no longer the expectation of a stretch of an unscheduled three months. Their school friends tell competitive stories of carefully planned vacations, spending time traveling to all of the local attractions—various parks, the zoo, the science center, all of the festivals which come breezing through town. On the very first day of school they will be asked to list their favorite activities of the summer and no longer are these lists filled with things like finding wood to make a bridge over a creek or a day spent in imaginative play with their siblings. The lists are now full of trips, overscheduled days and “camps” that no longer offer a stay in nature.

    Our children have become used to being entertained every minute. In our house, we have limits on electronics and kick the kids outside on a nice day. Even as we try as parents to set limits and get our children out in nature, the new cry of childhood seems to be “I'm bored,” which is not really just meaning “I'm bored,” “but “Please find something to entertain me, as I no longer can entertain myself even for a short period of time.” Our children no longer know how to sit in silence, entertain themselves while even waiting for a few minutes and have lost the awe of nature as they have become addicted to screen time.

    We have made a choice in this household to do what is no longer expected of children in many households—we will ensure that there are days of “boredom.” We refuse to spend our days scheduling our children's every hour. There will be many days with no plans at all, when they will be sent outside with only the grass and the trees and their own imaginations to entertain them.

    The screens will be turned off and our children will find that times of quiet can be just as or even more entertaining. They will bond with their brother and sister, making memories that they will replay in their minds well into adulthood. Even though sunscreen will be religiously applied, they will leave summer with sunburned and scratches coming from climbing trees, stomping through creeks and chasing the dog in the field.

    This summer I will be giving my children the greatest gift of all—boredom. For inside boredom is the gift of getting to know your own mind, of finding comfort and joy in nature and in the realization that the greatest gifts are experience, not things.

    Tablets(平板电脑) are useful devices, but their big screens always make them as a burden to carry around without a bag. Wouldn't it be great if there were a phone with the powers of a tablet that could be folded up and fit neatly into the hand? Now something like a tablet-shaped but foldable(可折叠的) phone is about to become available. In February, Samsung and Huawei both introduced foldable phones, the Galaxy Fold and Huawei Mate X separately, to the public for the first time. Mobile phone use has entered the "foldable future", the Verge noted.

    The technology could change our lives in significant ways. These devices, due to their bendable screens, give us the larger screens we want but still fit easily into the pocket. The technology could change other devices too. For example, we could make TVs that stick to walls like posters, or fold up easily to hide away in drawers, which could help increase available space to the maximum. In a keynote address, Justin Denison, Samsung's senior vice president, called the foldable screen "the basis for the smartphone of tomorrow". "It's a blank canvas (画布) for us to do something beautiful together," he said.

    So is there nothing to stand in the way of the foldable future? According to tech news website Android Authority, the necessary displays were difficult to produce. In 2012, nine out of ten foldable screens produced were defective or unusable. Today, that 10 percent rate has been improved to almost 90 percent. However, at present these foldable devices are expensive. For example, the price of Huawei Mate X is 17, 500 RMB. That's a price that few people will be able to afford.

    But if the foldable device isn't going to change the world overnight, there is no doubt that it is coming. Patrick Moorhead, an industry expert told The Verge, "Few are debating if foldable mobile displays are the future of smartphones; the only question is when and by whom."

Terrific New Technologies

•A fashionable smart speaker

    The new Amazon Echo smart speaker has the same popular feature as the original-an always listening voice assistant ready to play music and news, set timers, and use third-party apps. Only now it's actually stylish. The $120 speaker comes in different finishes, including fabric and wood.

•A helping hand for parents

    10 Suzy Snooze helps babies and kids sleep so parents can catch up on their own sleep. It's a sound machine and a nightlight. It connects with an app over wi-fi and turns into an audio monitor. If a kid cries at midnight, it'll detect the sound and try to calm him back to sleep. It can also let early risers know when it's OK to get out of bed. Made by Bleep Bleeps, the $249 "smart nightlight" has an adorable little face.

•Safety for ding dongs

    Doorbells used to just ring, ding, and dong. But thanks to modern technology, doorbells can now double as Internet-connected- surveillance(监视) devices. Rings $249 Video Doorbell Pro can record HD video of your front steps, even at night. It includes motion sensors and two-way audio, so you can yell "get off my lawn" from anywhere. You can also use the app to see what's going on in front of your house while you're at work or in the backyard.

•The must-have kitchen gadget

    The Instant Pot makes food fast in one pot. The surprise kitchen hit is a combination of pressure cooker, rice cooker, slow cooker and even yogurt maker. It has sensors and settings to make cooking as safe as possible. Starting at $80, an Instant Pot can make dishes in less time than it typically takes to cook them.

With such a strong artistic heritage, it's no surprise that England knocks it out of the park when it comes to world-class art galleries. These are the galleries you need to add to your must-visit list.

Royal Academy of Arts (RA), London

Not your standard gallery, the Royal Academy of Arts is led by artists to promote not just the appreciation of art, but its practice. It is world-famous for hosting some exhibitions that get everyone talking. Besides, what sets the RA apart is its engagement with the public through participatory experiences, allowing visitors to not only view art but become part of it in innovative ways.

Sainsbury Centre for Visual Arts, Norwich

Sitting on the edge of the University of East Anglia's campus, the Sainsbury Centre holds a collection of remarkable works of art spanning over 2,000 years. Inside the seminal Norman Foster building, you'll find artworks from around the world, including some stunning pieces of European modern art by Degas, Francis Bacon, and Alberto Giacometti.

Yorkshire Sculpture Park, West Yorkshire

Tearing up the rulebook when it comes to how we traditionally view art, the Yorkshire Sculpture Park strives to break down barriers by showing works from British and international artists in the open air. Set in hundreds of acres of West Yorkshire parkland, you'll see sculptures by some of the leading artists of the 20th century.

Whitworth, Manchester

After a sky-high £15 million development, the Whitworth is becoming one of the premier galleries in the north of England. Making full use of its picturesque park setting, the gallery has a beautiful art garden and a sculpture terrace (露台), all waiting to be explored. Inside the gallery, you can view an exciting programme of ever-changing exhibitions.