3 . As the effects of climate change become more disastrous, well-known research institutions and government agencies are focusing new money and attention on an idea: artificially cooling the planet, in the hopes of buying humanity more time to cut greenhouse gas emissions.

That strategy, called solar climate intervention (干预) or solar geoengineering, involves reflecting more of the sun’s energy back into space — abruptly reducing global temperatures in a way that imitates the effects of ash clouds flowing out from the volcanic eruptions. The idea has been considered as a dangerous and fancied solution, one that would encourage people to keep burning fossil fuels while exposing the planet to unexpected and potentially threatening side effects, producing more destructive hurricanes, wildfires floods and other disasters.

But. as global warming continues, producing more destructive hurricanes, wildfires floods and other disasters, some researchers and policy experts say that concerns about geoengineering should be outweighed by the imperative to better understand it, in case the consequence of climate change become so terrible that the world can’t wait for better solutions.

One way to cool the earth is by injecting aerosols (气溶胶) into the upper layer of the atmosphere. where those particles reflect sunlight away from the earth. That process works, according to Douglas MacMartin, a researcher at Cornell University.

“We know with 100% certainty that we can cool the planet,” he said in an interview. What’s still unclear, he added, is what happens next. Temperature, MacMartin said, is an indicator for a lot of climate effects. “What does it do to the strength of hurricanes?” he asked, “What does it do to agriculture production? What does it do to the risk of forest fires?”

Another institution funded by the National Science Foundation will analyze hundreds of simulations of aerosol injection, testing the effects on weather extremes around the world. One goal of the research is to look for a sweet spot: the amount of artificial cooling that can reduce extreme weather events without causing broader changes in regional rainfall patterns or similar impacts.

4 . The second little pig was unlucky. He built his house from sticks, which was blown away by a wolf. His brother, by contrast, built a wolf-proof house from bricks. The fairy tale could have been written by an agent for the construction industry, strongly favoring brick, concrete and steel. However, in the real world it would help reduce pollution and slow global warming if more builders copied the wood-loving second pig.

No other building material has environmental credentials (认证信息) as exciting and overlooked as wood. The energy required to produce a laminated wooden beam (层压木梁) is one-sixth of that required for a steel one of comparable strength. As trees take carbon out of the atmosphere when growing, wooden buildings contribute to negative emissions by storing the stuff. And for refitting older buildings to be more energy efficient, wood is a good insulator (绝缘体). A softwood window frame provides nearly 400 times as much insulation as a plain steel one of the same thickness and over a thousand times as much as an aluminium (铝) equivalent.

But such bigger stories are still uncommon. Governments can help push the industry to use more wood, particularly in the public sector — the construction industry’s biggest client. That would help wood-building specialists achieve greater scale and lower costs. Zero-carbon building regulations should be altered to take account of the emissions that are presented in materials.

Construction codes could be regulated to make building with wood easier. Here the direction of travel is wrong. Britain, for instance, is banning the use of timber on the outside of tall buildings after 72 people died in a tower fire in London in 2017. That is a nonsense. Grenfell Tower was covered in aluminium and plastic, not wood. Modern cross-laminated timber (交叉层叠木板) panels perform better in fire tests than steel ones do.

Carpentry alone will not bring the environmental cost of the world’s buildings into line. But using wood can do much more than is appreciated. The second little pig was not wrong, just before his time.

5 . Many Beijing residents go to great lengths to avoid breathing the city's smoggy air, especially when it reaches critical pollution levels, but one local entrepreneur decided that canning(灌装) and selling this poor quality air as a souvenir would be a great idea. Believe it or not, he was right.

After seeing a number of companies achieve commercial success by canning fresh air from countries like France, Canada or Australia and selling it in China, Dominic Johnson-Hill, a British-born citizen of Beijing and owner of the Plastered 8 souvenir shop, decided to turn the idea on its head and sell canned Beijing air throughout China and abroad.

"I'd seen people going crazy to buy canned air from Canada and Australia, so I thought it was time to push business the other way," the entrepreneur said. "They' re perfect gifts! What else are you going to take home when you go home from Beijing? A roast duck? A Plastered T-shirt? These cans are light, portable, you can just imagine someone' s face when they unwrap (打开) it for Christmas."

The few mouth-fulls of Beijing air come in standard tin cans featuring a couple of iconic city landmarks as well as a bitter description of the contents: "a unique mix of nitrogen, oxygen and some other stuff". The ironic (讽刺的) souvenirs cost 28 RMB (US $4) and are available at the Plastered 8 shop, as well as on its online shop. But if you're actually considering buying some, you'd better ask shop in advance, as they are virtually flying off the shelves. Johnson-Hill said that his shop is selling hundreds of Beijing air cans every day.

Personally, the well-sold can probably is an awakening for the public to be concerned about the living conditions. Yet one thing that’ s not particularly clear is whether the air is really collected from Beijing, as the cans are labeled as "Made in Shenzhen". There's a big chance that' s just a kind of Plastered 8 humor, as they also list "Choking Hazard" and "May have unidentified objects inside." as warnings.

Anyway, it is probably a unique way to arouse public awareness of protecting the environment.

6 . One evening, Catherine was at home as usual. As her____swung between what she was going to do with her life and their dinner plans for the evening, she was unexpectedly ___by an urgent call from her sister “Get over here! Turn on NBC and check these guys out. They are just like you…” One Facebook message and a phone interview later, Catherine____herself on a bus with 8 strangers in the middle of the sweltering desert heat of Utah, picking up trash and ___awareness about zero-waste and climate change.

With a deep____of the environment and a desire to make a __ , Catherine, Davey, and a group of self ___“environmental pick-up artists” went on a coast to coast road side trash pick-up. As they walked, sometimes only______0.9 miles in an entire day, they ____ and steadily made their way across the United States for three years, picking up a total of 201,678 pounds of trash.

Catherine and Davey____with us wonderful stories of hope and inspiration that fueled their___to continue their journey. After spending weeks silently______how she would have enough _____to fly home for their two-week spring break, Catherine found a blank, unidentified envelope____with $850 cash in the desert. Just enough to get her home and back. After their bus____outside of Denver, they unexpectedly got ____ and arrived in Yosemite National Park three weeks later, just in time for the “Yosemite Facelift” where____ from all over the state came together with a______of cleaning up trash all over the park.

Being at the right place at the right time became almost normal, and they realized that much of what they ____was more than just a coincidence. Together, their team learned to simply ____themselves to their task, and surrender to the journey.

Litter is everywhere，doing great harm     1     the environment and life on our planet.Jeff Kirschner，who wants to build a litter-free world，started a global community named Litterati     2       (settle)this problem.

The story began with his 6-year-old daughter.One day they were going on a hike when the girl noticed a     3     (break)plastic tub(浴盆)in a river.She said，“Daddy，that doesn’t go there.”That took Kirschner by surprise.He，like many adults，had become so used to the rubbish around them that he hadn’t given it a second look.    4     his daughter said reminded him of the serious problem our planet faces.

Jeff started to take       5    (act).He created Litterati，an app that makes it fun to pick up litter.The idea is       6    (fair) simple:Spot a piece of trash，take a photo，post the photo online and then put the litter into dustbins.

    7     (see)that Jeff was keeping a record of the positive impact he was having on the planet，people worldwide started participating.Up to now，over 2，500，000 photos posted by 3,500 people from over 40 countries     8     (find)their way to Litterati’s digital landfill.

Litterati is more than an app.It is a highly     9     (effect)solution to a pressing issue.Wherever you live，whatever you do and       10     you are，join Litterati to make the world a cleaner and healthier place to live in.