Glaciers occupy over     1    tenth of Iceland. As temperatures rise across the Arctic nearly faster than any place on the planet, all of Iceland     2    (consider) the changing landscape and climate a matter of national     3    (urgent), and trying to deal with the prospect of a future with no ice. Energy producers are upgrading hydroelectric power plants and experimenting with burying carbon dioxide in rock to keep     4     out of the atmosphere. The fishing industry is reducing fossil fuel use with energy-efficient ships.The government is budgeting $55 million over five years for reforestation, land conservation and carbon-free transport projects    5    (reduce) greenhouse gas emissions. More     6    (spend) by 2040,     7     Iceland expects businesses, organizations and individuals to be removing as much carbon dioxide    8    the atmosphere as they put in. “Climate change is no longer something to be joked about in Iceland or anywhere,” Gudni Jóhannesson, Iceland’s president, said in an interview,    9    (add) that most Icelanders believe human activity plays a role. “We are taking responsibility to seek     10     (practice) solutions. But we can do better,” he said.

6 . What do the following animals have in common? Pandas, rhinoceros, Mexican burrowing snakes, pink pigeons and small tooth sawfish.

They are all endangered animals! Animals become endangered for a variety of reasons. Sadly, humans are behind every one of them!

For centuries, humans have hunted elephants for their tusks, and killed tigers for their beautiful fur, caught fish for food. While we still have elephants, tigers, and fish in the wild, we cannot say the same about many others that have simply died out!

Year 1505 was a dreadful turning point in the natural history of the island of Mauritius — European sailors discovered this beautiful island in the Indian Ocean and brought dogs, pigs, monkeys with them. The arrival of humans and those introduced animal species were bad news for dodo birds. About 50 pounds and flightless, dodo birds did not have any natural enemies until then. They picked fruit fallen from trees and built their nests on the ground. Shortly after humans set foot on Mauritius, however, dodo birds realized that they were in big trouble — men killed them for their meat, and those introduced animal species destroyed their nests and ate their eggs. The effects of excessive hunting and foreign species drove dodo birds to first become much fewer and then die out. The last dodo bird was killed in 1681.

Humans and animals have always competed for land and other natural resources. We clear an area of a forest for farming. We cut down trees and use wood to build beautiful houses. We build reservoirs to make sure that we have enough water to use. At the same time that we are trying to make our life comfortable, we destroy the habitats of wild animals.

More than once we have seen on television that rescue workers are trying their best to save seabirds in spilled oil. More than once we have heard about how emissions of carbon dioxide (二氧化碳的排放) and other gases have raised the earth's temperature and caused global warming. Pollution has a serious and long lasting effect. If we choose to do nothing and continue to pollute our planet Earth, our next generations will have to face an Earth without birds singing and beasts roaring.

8 . Earth’s natural resources include air, minerals, plants, soil, water, and wildlife. Conservation is the care and protection of these resources so that they can survive for future generations. It includes maintaining diversity of species, genes, and ecosystems, as well as functions of the environment, such as nutrient cycling.

Continued human population growth has led to unsustainable rates of consumption of our natural resources, resulting in a loss of Earth’s biodiversity. The main factors driving biodiversity loss include habitat destruction, climate change, invasive (入侵的) species and pollution.

Declining biodiversity is closely intertwined with species extinction. While extinction is a normal process of nature, the rate at which it is happening today is not. Scientists estimate that current extinction rates are about a thousand times higher now than would be expected based on the fossil record, and that we may be experiencing a mass extinction event, which is when 75 percent or more species are lost at a time.

The extinction of the passenger pigeon is a famous example of an extinction caused by human activity. It was once the most richest land bird in North America, with a population of approximately three to five billion when Europeans arrived. Despite its vast numbers, this pigeon became extinct in the wild by the 1900s because of overhunting. The last individual bird, named Martha, died in captivity in 1941 at the Cincinnati Zoo.

Conservation practices and policies—ranging from the removal of invasive species, to setting aside protected land for wildlife and plants, to establishing the U. S. Endangered Species Act (ESA)—have been put in place to deal with these extinction pressures. Currently, more than 26,500 species are estimated to be at risk of extinction, though the exact number is difficult to calculate.

9 . Chemists have spent the past century trying to make plastics break down in seawater. Most plastics take centuries to fully break down in the ocean.     1     However, this may change. Scientists have designed a new kind of plastic that can break down in seawater within weeks, not decades or more.

    2     It is known as polylactide (聚乳酸) or PLA. It’s made by linking many building blocks into a long string. Scientists had hoped PLA would quickly break down in the environment. And in some places it does, but not in seawater. After three years in the ocean, LA remains largely unchanged.

Timo Rhein Berger is a PhD student at the University of Twente in the Netherlands.     3       For part of that work, he became part of a team that just added some biology-inspired breaking points to PLA. They put those breaking points to places where monomers (单体) in the PLA molecules are linked. Then, they soaked (浸泡) their samples in artificial seawater. In this way, they measured how fast the PLA broke down. As the team had hoped, seawater attacked the weakened links between monomers. That could tear the PLA chain apart.     4    

When the researchers weakened 15% of PLA’s monomer links, the PLA broke down entirely within just two weeks. When they weakened only 3% of the links, the breakdown took about two years.     5     This can be achieved by adjusting how many weakened links it has.

China’s First National Park

China’s first national park in Northwest of China’s Sanjiangyuan area,     1     (cover)a total area of 123,100 square kilometers, was officially established in 2020     2     schedule. The national park is the country’s calling card, and unlike nature reserves,     3     protect unique species, national parks stress the protection of the entire ecosystem.

Under the national park management, herders and     4     (farmer) will be turned into the forces of     5     (environment) protection in the Sanjiangyuan area. The work     6     (expect) to provide jobs, boost incomes and give people an     7     (encourage) to protect the environment. The ecological environment of the Sanjiangyuan area has greatly improved in recent years. The grassland coverage of the area has risen sharply     8     (compare) with the last decade. The last decade also saw a significant increase in the number of wild animals, because the number of Tibetan antelopes     9     (be) over 70,000 from less than 20,000 in     10     1980s.