Many of the world’s islands were previously unexplored places, but over time, people have come to these places with far-reaching effects, including deforestation, over-hunting and the introduction of invasive species. ___________, most of the bird species disappeared.

While the death of many birds since the 1500s has been ___________, our knowledge of the fate of species before this relies on fossils, and these records are limited because birds’ lightweight bones are _________ over time. This conceals (隐瞒) the true ___________ of global extinctions.

Researchers now believe 1,430 bird species — almost 12 per cent — have died out over modern human history since around 130,000 years ago, with the vast majority of them becoming extinct directly or indirectly _________ human activity.

The study, led by the UK Centre for Ecology & Hydrology (UKCEH) and published in Nature Communications, used statistical modelling to _________ the undiscovered bird extinctions.

Lead author Dr Rob Cooke, an ecological modeler at UKCEH, says: “Our study demonstrates there has been a far higher _________ impact on diversity than previously recognized. Humans quickly destroyed bird populations through habitat loss, over-exploitation, and the introduction of rats, pigs, and dogs, which attacked the birds’ nests, and ___________ with birds for food. We show that many species became extinct before written records and left no ___________, lost from history.”

Dr Soren Faurby of the University of Gothenburg, a co-author of the study, adds: “These historic extinctions have had a major impact on the current biodiversity crisis. The world may not only have lost many fascinating birds but also their varied __________ roles, which are likely to have included key functions such as pollination (授粉). This will have had knock-on effects on ecosystems, so, ____________ bird extinctions, we will have lost a lot of plants and animals that ____________ these species for survival.”

Observations and fossils show 640 bird species have been driven extinct — 90 per cent of these on islands ____________ by people. These ____________ from the iconic Dodo of Mauritius to the Great Auk of the North Atlantic to the lesser-known Saint Helena Giant Hoopoe. But the researchers estimate there have been further 790 unknown extinctions, meaning a total of 1,430 lost species — leaving just under 11,000 today. Therefore, from the perspective of protecting species ____________, the protection of birds is an urgent issue for mankind.

Afroz Shah, a lawyer in Mumbai, hasn’t had a weekend off in four years. But he hasn’t spent this time preparing for_____. His mission( 使命)? Saving the world’s oceans from____ pollution.

It’s a calling he found in 2015 after moving to a community in Mumbai called Versova Beach. He had played there   as a child and was _____to see how much it had ______. The sand was no     longer___ because it was covered by a layer of garbage — most of it is plastic waste.

“The whole beach was like a _____ of plastic,” he said, “It hurt me.” The ______ mess Shah had seen is part of a global environmental crisis. Tons of plastic ______in the world’s oceans each     year. “Plastic in the ocean is a____. And the sea-species have no choice at all,” Shah said, “We are __ their habitats.”

In 2015, Shah began picking up plastic waste from the _____every Sunday morning. At first, it was just him and   a neighbor, and then he began   calling on others to join in. Word _____and with help from social media, more volunteers____.

For Shah, the work has always been a _____   journey, but it has earned global attention. After he   was _____as a Champion of the Earth in 2016, Shah now devotes his free time to this ______.   He’s   spent 209 weekends on this mission, ____   more than 200,000 volunteers to join him. By     October 2018, Versova   Beach was _____clean and Shah’s cleanups expanded to another beach.   “This world talks too much. I think we must talk _____   and do action more,” he said when     interviewed by CNN in October 2019. “I see___ with these youngsters rising up.”

With vigorous promotion and extensive participation over the past two years, waste sorting is a new trend that has reshaped the image of campuses across Beijing.

“In the past, sanitation workers sorted the garbage next to the trash cans near the dormitory, _________ a disgusting odor. On windy days, the trash was blown everywhere and we always _________ around it with our hands covering our noses,” says Sun Jiajing, a sophomore at Beijing Forestry University. “Now, we are more active in classifying waste.”

Since a revised guideline on household waste disposal in Beijing was _________ on May 1, 2020, many students have seen their campuses take on a new look that is more pleasant, tidy and appealing.

At Beijing Forestry University, about one in four students are trash-sorting volunteers.

In the Beijing No 20 High School, bins to recycle waste are placed on each floor and students on duty will set their wits to turning trash into _________.

“I received training on trash classification before taking on the role as head of the trash-sorting station. My job is to remind everyone to classify waste and recycle to the best _________,” says Ding Shuyi, a student at the school.

As China pushes _________ the “double reduction” education policy, which aims to ease the burden of _________ homework and off-campus tutoring for primary and middle school students, understanding of waste sorting has been fused into academic teaching via various innovative approaches.

“Our Chinese teachers encourage students to write poetries _________ on waste classification, math teachers lead them to do math on topics such as water conservation, while our music teachers choreographed a ‘waste sorting’ dance with the students,” says Zuo Chunyun, principal of a primary school in the suburban Tongzhou district of the capital.

Zuo adds that students in senior classes will join trash-sorting projects and map out _________ in the form of handwritten newspapers and mind maps. Decorations made from recycled materials are exhibited in the school’s corridors.

The same scene can be seen in Qianjin Primary School, Haidian district. “Garbage can be turned into __________,” says Wang Liping, the principal. “We have raised 100,000 yuan ($15,760) of charity funds by encouraging students and their parents to recycle waste, and the money was used to purchase movie screens for schools in Hotan, Xinjiang.”

According to Liu Jianguo, a professor at Tsinghua University, the implementation of garbage sorting depends on the __________ participation and unremitting efforts of society, which is conducive to the__________ of social civilization.

“Wide participation of students and school staff will help promote garbage sorting to become a new fashion in society,” adds Liu.

Official data shows that over 90 percent of the residents in Beijing have participated in waste classification, and about 85 percent can __________ categorize the garbage. But still, relevant departments are __________ to further raise the ratio.

“Our next move will be more precise supervision of groups that did __________ poorer jobs in sorting out garbage,” says a staffer with the Beijing Municipal Commission of Urban Management.