Boyan Slat, a Dutch inventor is cleaning the world’s most polluted rivers in an effort to save the oceans. He has made it his mission    1    (remove) plastic from the oceans. His organization, The Ocean Cleanup, has successfully started to clean the pollution that has been circling in the Great Pacific Garbage Patch. But millions more tons of plastic enter the oceans every year, almost all of it     2     (flow) from rivers.

Just 10 rivers are responsible for around 90% of all that plastic,     3    a 2017 study from the Helmholtz Centre for Environmental Research. “So     4    we focus on the worst rivers, we believe we can really have the fastest and most cost-effective way to close the tap and prevent more plastic from reaching the oceans in the first place,” Slat said.

The Ocean Cleanup is effectively using floating trash collectors called “Interceptors”. These solar-powered, autonomous systems use the rivers’ currents to guide the trash onto a conveyor belt that carry the waste to     5     (await) bins.

The first interceptor went to work in Jakarta, Indonesia, to pull plastic from a waterway called the Cengkareng drain. A second interceptor began collecting trash flowing down the Klang river in Kuala Lumpur, Malaysia. On the other side of the world,     6    Interceptor has recently started removing river pollution near the mouth of the Rio Ozama in the Dominican Republic.

“    7    the river is polluted, the fish die. Every year there are less fish,” Luis Peguero, a local fisherman, explained. When Peguero is lucky enough to reel in (收线拉起) a catch, it     8    not be safe for his family to eat. “You find stuff in the fish, especially the catfish. Trash, bottle lids, even a shoe. The fish can’t survive this,” said Peguero. To him, the modern trash-collecting catamaran (双体船) is a peculiar but welcome sight.

The Ocean Cleanup is working with the local governments and communities to help retrieve (取回) the plastic the Interceptors collect. “By stopping plastic in rivers, we hope to not only address the big global plastic pollution issue, but also really help make life better for the people    9    live near these problematic rivers,” said Slat.

The Ocean Cleanup’s goal is to tackle the thousand most polluted rivers within 5 years. Soon interceptors     10     (head) to Vietnam, Thailand, Jamaica and Los Angeles County in the United States.

“We are getting out tons of plastic every single day,” Slat said. “We accept that we won’t deliver magic in one go. But we’re doing this, step by step.”

The world has warmed more than one degree Celsius since the Industrial Revolution. The Paris climate agreement hoped to restrict warming to two degrees. The     11     of succeeding, according to a recent study based on current emissions trends, are one in 20. If by some miracle we are able to limit warming to two degrees, we will only have to negotiate the extinction of the world’s tropical reefs,     12     the sea-level rise of several meters and abandon the Persian Gulf. The climate scientist James Hansen has called two-degree warming “long-term disaster”, which is now the best-case scenario. Four-degree warming will mean “short-term disaster”: Europe in permanent drought; vast areas of China, India and Bangladesh claimed by desert; the American Southwest largely     13    .

In the decade that ran from 1979 to 1989, we had an excellent opportunity to solve the climate crisis. The world’s major powers came within several signatures of     14     a global framework to reduce carbon emissions — far closer than we’ve come since. During those years, the conditions for success could not have been more     15    . The obstacles we blame for our current inaction had yet to emerge. Almost nothing stood in our way — nothing except ourselves.

Nearly everything we understand now about global warming was understood in 1979. Human beings have altered Earth’s atmosphere through the     16     burning of fossil fuels. At the start of the 1980s, scientists within the federal government predicted that     17     evidence of warming would appear on the global temperature record by the end of the decade, at which point it would be too late to avoid disaster. A report prepared by the National Academy of Sciences advised that “the carbon-dioxide issue should appear on the international     18     in a context that will maximize cooperation and minimize political controversy and division.” If the world had adopted the proposal widely supported at the end of the ‘80s, warming could have been held to less than 1.5degrees.

But they failed, even though the world’s leading oceanographer Henry Stommel and the Harvard planetary physicist Richard Goody, whose mere presence could inspire     19    , tried to warn humanity of what was coming. They risked their careers in a painful campaign to solve the problem, first in scientific reports, later through     20     avenues of political persuasion and finally with a strategy of public shaming. Their efforts were passionate and they failed. Now it is our turn.

What is the Great Pacific Garbage Patch?

The Great Pacific Garbage Patch (GPGP) is the largest of the five offshore plastic accumulation zones in the world’s oceans. It is located halfway between Hawaii and California.

PLASTIC __________

It is estimated that 1.15 to 2.41 million tonnes of plastic are entering the ocean each year from rivers. More than half of this plastic is less __________than the water, meaning that it will not sink once it encounters the sea.

The strong and floating plastics show resiliency(韧性) in the marine environment, allowing them to be transported over __________distances. They persist at the sea surface as they make their way off shore, transported by converging (汇聚的) currents and finally accumulating in the patch.

Once these plastics enter the gyre（环流）, they are unlikely to leave the area until they __________into smaller microplastics under the effects of sun, waves and marine life. As more and more plastics are discarded into the environment, microplastic __________in the GPGP will only continue to increase.

LOCATION

Due to seasonal and interannual variabilities of winds and currents, the GPGP’s location and shape are constantly changing. Only floating objects that are __________influenced by currents were likely to remain within the patch.

By simulating concentration levels in the North Pacific, the researchers were able to follow the location of the patch and found on average it orbits around 32°N and 145°W. However, the team observed seasonal __________from west to east and substantial variations in latitude（纬度）depending on the year.

IMPACT ON WILDLIFE

Plastic has increasingly become a very common substance in the ocean. Due to its size and color, animals __________the plastic for food, causing malnutrition; it poses entanglement（缠绕）risks and threatens their overall behavior, health, and existence.

Studies have shown that about 700 species have encountered marine debris, and 92% of these __________are with plastic. 17% of the species affected by plastic are on the International Union for Conservation of Nature Red List of Threatened Species.

IMPACT ON HUMANS AND SOCIETY

Once plastic enters the marine food web, there is a possibility that it will contaminate the human food chain as well. Through a process called bioaccumulation, chemicals in plastics will enter the body of the animal __________on the plastic, and as the feeder becomes prey, the chemicals will pass to the __________—making their way up the food web that includes humans. These chemicals that affected the plastic feeders could then be __________within the human as well.

__________, yearly economic costs due to marine plastic are estimated to be between $6-19billion USD. The costs __________its impact on tourism, fisheries and aquaculture, and governmental cleanups. These costs do not include the impact on human health and the marine ecosystem due to __________research available.