1 . Dry lightning(雷电)can still be harmful even when conditions aren’t so dry, said a study published in Geophysical Research Letters last month. Dry lightning during little to no rainfall was previously thought to cause wildfire danger only with less than 2.5mm of rain in a day. A Washington State University-led study of wildfires in the US West found dry lightning caused wildfires despite up to 7.7 mm of rain.

“The rainfall amounts we recorded should help provide a better understanding of just how much rain can cause a fire risk,” said Dmitri Kalashnikov, lead author of the study.

The researchers analyzed(分析)cases on more than 4,600 naturally caused fires from 2015 to 2020. They matched 3,726 of those to the lightning strikes that likely started them with the help of National Lightning Detection Network.

The study found that 15.3% of those were holdover fires which burn without smoke, bringing about over a hundred fires each year. Analyzing the rainfall amounts around the time of the lightning strikes showed greater rainfall than previously thought among the earlier found fires ranging from 1.7 mm to 4.6 mm.

While humans still cause most fires either by accident or on purpose, lightning-caused wildfires burn the most areas. Nearly 70% of the wildfire-burned land in the West was from lightning-caused fires according to the study. For example, the largest wildfire burn area in California history took place in August 2020 after dry lightning caused many wildfires at once.

Dry lightning can also start wildfires in places that are hard for firefighters to reach. This study found the places where holdover fires happened repeatedly were in the forested mountains of the Southwest as well as the middle and southern Rocky Mountains. Holdover fires cause the problem because they are so hard to notice.

2 . My 5-year-old daughter Kai walked around a bus stop, picking up candy wrappers and plastic bottles and throwing them in the waste bin. We were a visiting family here, but she was cleaning the sidewalk, which didn’t shock me, nor was I _________ when strangers looked at us.

Our cleanup project began when we drove past an empty field one day and Kai _________ the field was covered by _________ balloons. We had read about how animals could _________ balloons for food. “Stop,” Kai said, and I _________. Surprisingly, we found the field was full of much trash _________ the balloons. “Can we come back and clean it?” Kai asked. Then each Friday, we returned to have a(n) _________ cleaning.

However, it seems we can never _________ the trash completely. I feel something close to _________! Why are we making kids clean up our __________? It has everything to do with the planet we adults are leaving for kids. Plastic pollution is globally distributed and microplastics have even been discovered in human blood. It is not a __________ story that we have created trash but our next generation cleans up them.

Now Kai hopes to become a marine biologist to protect sharks one day. She still has many years to __________, if adults get serious about solving plastic pollution. We shouldn’t leave our next generation a __________ planet and expect them to save it.

The last time our family was at the beach, we still picked up plastic bottles. Most __________, though, we saw an octopus (章鱼) playing around our feet, a __________ of a harmonious habitat worth protecting.

Wuyi Mountain, as a national nature conservation area, is well-known for its clear water and beautiful peaks. There is little doubt    1    it attracts millions of tourists from home and abroad annually.

But I’m concerned that the increasing number of tourists has had a negative impact    2    the environment. Garbage    3    (throw) around. Enterprises producing tourism-related products burn fossil fuels,    4    (cause) smog in the air. Restaurants release oily water into the river, making it dirty and smelly. “What should I do to help restore the    5    (harmony) ecological system here?” That is what I have been thinking about. Therefore, on behalf of the students of our school, I put forward the following suggestions.

To begin with, the government is supposed to adopt     6    (policy) to restrict the volume of tourists. Next it can carry out inspections into enterprises    7    (regular) and fine those who fail to solve pollution problem properly.

In addition, it is also the government’s responsibility    8    (seize) every opportunity to educate people to reduce their carbon footprints. It’s believed that if the government takes appropriate actions and    9    (put) environmental reforms in effect, we won’t have to be trapped in this environmental chaos. Only then can Wuyi Mountain head towards    10     sustainable future.

5 . Don’t call Madison Stewart an environmentalist. She sees herself simply as an individual taking action in defense of something she loves that’s in need of protection.

Despite her youth, the 24-year-old is an undersea veteran (老手). She grew up sailing around the Great Barrier Reef on her parents’ boat and spent her early life free diving while patiently waiting for the day when she could get her scuba diving (水肺潜水) certification, aged 12. Already impressed by sharks, Madison was now pleased to be able to observe them in their own world. “I got to know the sharks...I could recognize them by sight,” Madison says. “Other people had dogs around them growing up. I had sharks.”

But within a couple of years, she saw a great reduction in shark numbers on the reef. “One day I went in the water and couldn’t find my sharks anywhere, sharks I’d spent my childhood with,” she says. “They’d been caught and killed.” It was a great moment for Madison.

She left school at 14 to be homeschooled so she could spend more time in the ocean. She taught herself to shoot underwater video to document sharks in their own world and share her sense of wonder with others. She launched a YouTube channel and built a huge following for her documentaries where she focuses on issues like inadequate protection for some shark species and the global shark fin (鳍) industry.

In 2014 Madison was the subject of the encouraging documentary Shark Girl, which introduced her to a global audience. In 2017 she appeared as an “Ocean Guardian” in the documentary Blue that explored a lot of threats to the world’s marine environments, including the damaging effect of the global shark fishery. The film encourages viewers to get involved and includes practical steps to guide them to do so. It shows Madison’s philosophy that the power of the individual to make a difference by their own direct action should never be underestimated.

6 . What would you think is the most plentiful man-made material on earth? Steel, plastic, glass? The answer is concrete.

And while it’s an incredibly useful material existing everywhere, the energy intensive process of making concrete releases massive amounts of CO₂ into the atmosphere, and its main component, which is a mixture of rocks, sand, water and most importantly, cement (水泥) to glue it altogether, is responsible for 7 percent of global CO₂ emissions, leaving a huge carbon footprint. But without cement, concrete doesn’t hold up skyscrapers.

What if there was a way that instead of releasing carbon dioxide, concrete could trap it forever? Carbon Cure is kind of the brains of the technology. This innovation puts carbon dioxide into the concrete as it’s being mixed. When the concrete hardens, those otherwise harmful emissions are trapped forever, before they even reach our atmosphere. Christie Gamble, part of the team behind Carbon Cure’s technology, explained ,“ We actually transform the CO₂ into a mineral, and the real selling point is that the mineral itself improves the compressive (压缩的) strength for the concrete, which means producers like Thomas Concrete can use less cement in their mixtures and still achieve the same strength with fewer emissions.

Compression tests prove that the concrete made with Carbon Cure is just as hardy as the traditional stuff. If we can reduce 5 percent of the carbon footprint of the concrete industry, that’s a significant change from where we’re right now. Ultimately, if this technology was employed across the globe, we could reduce about 700 megatons of CO₂ every year, which is the same as taking 150 million cars off the road every year.

It’s going to change the way the concrete industry does things. Though companies pay to use Carbon Cure and buy CO₂ from a factory, they save money by using less of their most expensive cement.

Recycling plays     1     major role in fighting against pollution. By recycling paper, we not only save our trees, but we also recycle glass bottles, milk cartons and plastics. It is known to all     2     recycling preserves many non-renewable resources and reduces greenhouse gas emissions. Now cleaners send     3     (little) household waste to landfill sites than before and less energy is required when we are making new materials from old ones.

Health regulations once prevented recycled plastics from     4     (make) use of to make food containers but new technology has seen this ban lifted in some countries.

Rain water     5     (collect) from roads and roofs of buildings is also recycled. Water treatment plants treat    6    (million) of liters a day, removing bacteria and something unwanted. The recycled water cannot be drunk     7    can be used to wash cars, water trees and fight fires, etc. This     8     (mean) there is a reduced demand on drinking water supplies.

New technology is     9     (constant) improving recycling techniques in Europe, America and Japan, but countries with small populations may find that these new techniques are so expensive that they cannot     10     (put) into use in the immediate future.

10 . Poaching and habitat loss have threatened Africa's two species of elephants, taking them closer toward the edge of disappearance, according to a new report released by the International Union for Conservation of Nature(IUCN).

Before this update, Africa's elephants were grouped together and were evaluated as vulnerable by the IUCN. This is the first time the two species have been sorted separately. In the past, elephants were mostly considered as either Asian elephants or African elephants. Forest and savanna elephants were typically classified as subspecies of African elephants.

The African forest elephant is now listed as critically endangered and the African savanna elephant as endangered. The number of African forest elephants fell by more than 86% over a 31 -year assessment period. The population of African savanna elephants dropped by at least 60% over the last 50 years, according to the IUCN, which tracks the assessment risk of the world's animals. Africa currently has an estimated 415,000 elephants, counting the two species together.

Both elephant species experienced significant population decreases because of poaching. Although it peaked in 2011, illegal hunting still happens and continues to threaten elephant populations. African elephants also face continued habitat loss as their land is converted for agriculture or other uses.

There is some good conservation news, the IUCN points out. Anti-poaching measures, combined with better land use planning to support better human-wildlife relationships, have helped conservation efforts. Some forest elephant population figures have stabilized in well-managed areas in Gabon and the Republic of Congo and savanna population figures have remained stable or have been growing, particularly in the Kavango-Zambezi Transfrontier Conservation Area in southern Africa.

But with constant demand for ivory and increasing human pressures on Africa's wild lands, concern for Africa's elephants is high, and the need to creatively conserve and wisely manage these animals and their habitats is more severe than ever.