Five years ago, when I taught art at a school in Seattle, I used Tinkertoys as a test at the beginning of a term to find out something about my students. I put a small set of Tinkertoys in front of each student, and said: "Make something out of the Tinkertoys. You have 45 minutes today-and 45 minutes each day for the rest of the week."

    A few students hesitated to start. They waited to see what the rest of the class would do. Several others checked the instructions and made something according to one of the model plans provided. Another group built something out of their own imaginations.

    Once I had a boy who worked experimentally with Tinkertoys in his free time. His constructions filled a shelf in the art classroom and a good part of his bedroom at home. I was delighted at the presence of such a student. Here was an exceptionally creative mind at work. His presence meant that I had an unexpected teaching assistant in class whose creativity would infect other students.

Encouraging this kind of thinking has a downside. I ran the risk of losing those students who had a different style of thinking. Without fail one would declare, "But I'm just not creative."

"Do you dream at night when you're asleep?"

"Oh, sure."

"So tell me one of your most interesting dreams." The student would tell something wildly imaginative. Flying in the sky or in a time machine or growing three heads. "That's pretty creative. Who does that for you?"

"Nobody. I do it."

"Really — at night, when you're asleep?"

"Sure."

"Try doing it in the daytime, in class, okay?"

    Food production does great harm to our environment. There are many procedures involved in the manufacture of food that result in greenhouse gases and other pollutants. Some procedures require the consumption of large amounts of fossil fuels, such as the transportation and storage of food products. Other factors that cause great damage to our environment include the overuse of fresh water.

    The production of beef is more damaging to the environment than that of any other food we consume. Raising large numbers of cattle requires the production of large amounts of food for the animals. It's estimated that producing one pound of beef requires seven pounds of feed.

    Land use is also a problem. If the cattle are free-range cattle, large areas of land are required for them to live on. This has led to disastrous forest cutting and the loss of rare plants and animal species, particularly in tropical rain forests in Central and South America.

    Another problem specific to beef production is methane emissions (甲烷排放). Although many people are aware of the damaging effects of carbon dioxide, they don't realize methane's global warming potential is 25 times worse, making it a more dire problem.

    Unfortunately, beef consumption is growing rapidly. This is the result of simple supply and demand factors. Specifically, there are two main causes of demand that are encouraging the production of more supply. First, the increase in the world population means there are more people to consume meat. The second factor is socioeconomic advancement. As citizens in developing nations become financially stable, they can afford to buy more meat.

    Therefore, one way to reduce the greenhouse gas emissions is for people around the world to significantly cut down on the amount of beef they eat.

    Government in Tibet have denied the permanent( 永久的) closure of Mount Qomolangma National Nature Reserve.

    The announcement came after a report went viral online claiming the base camp of the world's highest mountain was "permanently closed due to heavy pollution" and caused a universal misunderstanding.

    Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33, 800 square km, it is home to one of the world's most weak ecosystems(生态系统).

    Kelsang, deputy director of the reserves administration, said ordinary tourists are allowed to visit areas around Rongpo Monastery, almost 5,000 meters above sea level. As for travelers who have a climbing permit, they can go to the base camp at an altitude of 5,200 meters. The mountaineering activities have been permitted by the regional forestry department.

    To conserve the environment surrounding Mount Qomolangma, China carried out three major clean-ups at an altitude of 5, 200 meters and above last spring, collecting eight tonnes of household wastes, human wastes and mountaineering trash. This year, the clean-up will continue, and the remains of mountaineering victims(受害者) above 8,000 meters will be centrally dealt  with for the first  time. Meanwhile, the number of people who stay at the base camp will be kept under 300.

Recently, there are 85 wildlife protectors in the reserve, and 1,000 herders have part-time jobs going around and cleaning up garbage.

These measures aim to strike a balance between various demands such as environmental protection, local poverty relief, mountaineering and education, said Wang Shen, county chief of Dingri at the mountain foot.

    Distance, just like currency, becomes incomprehensible when it reaches large quantities.

    So, when outdoor enthusiast and Midwest Mountaineering employee Elizabeth John says she only hiked the nearly 500 miles of the Colorado Trail over a period of six weeks, don't let her fool you. That's like walking from St. Paul to St. Louis—give or take a few dozen miles—plus thousands upon thousands of feet of altitude.

    "I'm a gardener, I'm a busy-hands person, but busy feet are just as good," she explains. "I don't meditate, but maybe that's the way I think about it—walking as a way to relax."

    John took childhood hikes in the Boundary Waters and caught her case of busy feet while hiking in Alaska as a teenager. With a background in paddling, mountaineering, and backpacking, she found long-distance hiking rewarding, though exhausting.

    Since then, thru-hiking—hiking a long-distance trail (考验，试验) end-to-end in one hiking season—has gotten friendlier to beginners. John has given up 60-pound packs in favor of a lighter modern backpacking equipment. For her 50th birthday, she decided to fly to Spain and walk close to 500 miles of the Camino de Santiago. The Colorado jaunt, her first solo long-distance hike, followed a few years later in 2017.

    "Going on a big walk is unreasonable and includes being uncomfortable, wet, hungry, sore, tired, lonely…it's challenging," she says. "It's a leap of faith. But I found the rewards surprising and unexpected, some even waiting for me at home after the trip. There is a rhythm to walking, a physicality and simplicity…a discovery."

    Logging some 4, 000 feet of elevation daily, John met many "trail angels" who provided shade, snacks, and sometimes beer at remote points in the wilderness, purely out of the goodness of their hearts. "You're so excited, because you're someplace so incredible, and it wasn't easy to get there," she says. "There was this moment when you love humanity, and you're so proud of people for doing it."

    Chocolate could soon be a thing of the past, after scientists warned that the cacao plant, from which chocolate is made, could be extinct within 32 years.

    Over half of the world's chocolate comes from just two countries in West Africa­Cote d'Ivoire and Ghana­where the temperature, rain, and humidity provide the perfect conditions for cacao to grow. But the threat of rising temperatures over the next three decades caused by climate change, is expected to result in a loss of water from the ground, which scientists say could upset this balance.

    According to the related data, a temperature rise of just 2.1℃ could spell an end for the chocolate industry worldwide by 2050. Farmers in the region are already considering moving cacao production areas thousands of feet uphill into mountainous area­much of which is currently preserved for wildlife. But a move of this scale could destroy ecosystems that are already under threat from illegal farming and deforestation.

    Part of the problem, according to Doug Hawkins, is that cacao farming methods have not changed for hundreds of years. "Unlike other tree crops that have benefited from the development of modern, high yielding strains and crop management techniques to realize their genetic potential, more than 90% of the global cocoa crop is produced by small farms with unimproved planting material," he said. "It means that we could be facing a chocolate decrease of 100,000 tons a year in the next few years."

    Now scientists at the University of California at Berkeley have teamed up with American candy company Mars to keep chocolate on the menu. Using the controversial(有争议的) gene-editing technology known as CRISPR they are trying to develop a type of the cacao plant capable of surviving in dryer, warmer climates. If the team's work on the cacao plant is successful, it could remove the need for farmers in West Africa to relocate to higher ground, and perhaps even allow cacao to be grown elsewhere in the world.