Last month, our school launched a campaign which intention was to promote environmental protection. The campaign last for one week. Firstly, there was a photo display to show the seriously pollution caused by human activities. Secondly, there was a lecture on many small step that we could take in our daily life protect the environment. For example, taking the bus and using the bike-sharing system would be a good way. Last but not the least, we students were encouraging to decorate our classrooms with recycled materials. Through the campaign, they have benefited a lot. We realize that it is our responsible to leave a better, cleaner and healthier planet for future generations.

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.

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.

6 . Styrofoam, or polystyrene, is a light-weight material, about 95 percent air, with very good insulation (隔热) properties, according to Earthsource. org. It is used in products from cups that keep your drinks hot or cold to packaging material that protects items during shipping. With the above good features, Styrofoam still enjoys a bad reputation. It cannot be recycled without releasing dangerous pollution into the air. The U. S. Environmental Protection Agency says it is the fifth-largest creator of harmful waste.

But now the common worms which are usually disgusting can come to the rescue, specifically, meal-worms. Scientists from the U. S. and China have discovered that meal-worms can digest plastic. One meal-worm can digest a pill-sized amount of plastic a day. Study co-author Wei-Min Wu says that in 24 hours, the plastic is turned into carbon dioxide.

Since Styrofoam has no nutrition at all, are the worms hurt by eating plastic? Much to the scientists’ surprise, the study found that worms eating Styrofoam were as healthy as worms eating bran (谷糠) . The researchers will study the worm’s eating habits and digesting system, looking to copy the plastic breakdown but on a larger scale. Once the way can be put into practice, it will make a revolutionary difference to the disposal of plastic.

“Solving the issue of plastic pollution is important”, says Wu, a Stanford University environmental engineering instructor. After all, our earth is small and landfill space-is becoming limited with too much garbage waiting to be dealt with, he says.

About 33-million tons of plastic are thrown away in the United States every year. Plastic plates, cups and containers take up 25 percent to 30 percent of space in America’s landfills. One Styrofoam cup takes more than 1 million years to recycle in a landfill, according to Cleveland State University.

8 . As heat waves continue to ravage the planet, air conditioners are becoming more and more common. However, these "active" cooling devices are posing problems because the electricity consumption which most people are concerned about and the release of ozone-damaging chemicals worsen the greenhouse gas effect, resulting in the creation of heat islands and further thermal pollution. Therefore, "passive" cooling, which doesn't have such effects, has attracted considerable attention from both scientists and ordinary people in recent years.

In a recent study, a team of researchers from China and US presented an eco-friendly, low-cost smart coating to keep buildings cooler while consuming zero electricity. Infrared radiation-based passive cooling has been investigated since 2014, but challenges, mainly the expensive and unsustainable design, have greatly limited their large-scale and widespread application. Besides, the imbalance in cooling ability of these coatings during the day and night tends to lead to great day-night temperature differences as more heat is lost than gained at night.

The solution therefore requires a "smart" mechanism that can both enhance daytime cooling and minimize nighttime heat loss. To do this, the researchers created a new smart coating comprised of conventional building materials, including titanium dioxide nanoparticles, fluorescent microparticles, and glass microspheres that were engineered to reflect most of the sunlight. Specifically, the titanium dioxide particles effectively reflect sunlight through light scattering（撒播）while the fluorescent particles increase the amount of reflection by changing the absorbed sunlight into fluorescence emissions, which drive more heat away from the building. Meanwhile, the glass microspheres re-send mid-infrared broadband radiation, allowing not only heat loss, but allowing heat exchange to take place between the building and the sky.

The coating was tested on a model concrete building. Through this efficient heat exchange with the sky, daytime cooling was strengthened while nighttime cooling was reduced. The building's inside temperature was always maintained at around 26℃, even when the out-side temperature varied from 24℃ to 37℃ during the day. We believe this new coating will make it to commercialization soon, enabling a sustainable, passive cooling technology that could help to fight climate change and the global energy crisis.

9 . 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.