1 . Nuclear pollution is a serious global   ___________, brought to the forefront by major accidents at Three Mile Island, Chernobyl, and Fukushima. These events have demonstrated the significant health and environmental risks _________by nuclear disasters. Not only have they caused immediate health problems, such as radiation sickness and increased cancer rates, but they have also _________lasting environmental damage and genetic changes in affected communities. As a result, nuclear pollution remains a pressing concern for governments, scholars, and individuals worldwide.

When nuclear accidents occur in coastal areas, the _________environment becomes a critical concern due to the crucial role that oceans play in _________the climate, ensuring food security, and supporting the livelihoods of billions of people globally. In recent years, the increasing threats to marine ecosystems from ocean pollution have _________public awareness of the need to protect the marine environment. Studies have shown that human activities pose a _________threat to marine environments, emphasizing the importance of improving environmental management and taking measures to mitigate environmental risks.

Following the Fukushima nuclear disaster in 2011, efforts to cool the reactors by pumping in seawater resulted in the _________of a significant amount of nuclear waste in the water storage tank at the Fukushima Nuclear Power Plant. _________attempts to manage this waste, the Japanese government’s decision to release nearly 1.26 million tons of nuclear wastewater into the Pacific Ocean over the next 40 years has faced opposition __________neighboring countries, local ____________, and international environmental organizations.

This __________poses serious risks to marine life, fisheries, and human health. Radioactive isotopes present in the wastewater, such as tritium, carbon-14, cobalt-60, and strontium-90, can accumulate in marine organisms and ultimately affect human populations through the food ____________. Therefore, there is an/a ____________need for further research and mitigation measures to __________the widespread impacts of nuclear pollution on the environment and human health.

2 . The world’s largest garbage dump doesn’t sit on some barren field outside urban centre. It resides thousands of miles from any land—in the Pacific Ocean.

The dump, known as the Great Pacific Garbage Patch, stretches for hundreds of miles across the North Pacific Ocean.     1    It has quickly come into the spotlight this year, thanks to growing media coverage and teams of scientists who took a voyage in August to study the patch.

    2    Shoes, toys, bags, wrappers, toothbrushes, and bottles too numerous to count are only part of what can be found in this dump floating midway between Hawaii and San Francisco.

But how did so much garbage get there?     3    The patch moves with the North Pacific Subtropical Gyre, a high pressure zone of air which forces ocean surface currents to move in a slowly clockwise pattern. This creates a whirlpool which sucks garbage problem: plastic that begins in human hands yet ends up in the ocean. Organic materials and garbage from other sources will eventually break down, but plastics do not, although they do break into smaller and smaller pieces.

    4    The area supports minimal sea life, because the garbage patch restricts the limited area of water which sea plants can live in. Other marine life including birds, mammals, fish and jellyfish also suffers because they mistake the garbage for food. A great deal of marine life is then consumed by humans, resulting in their ingestion of poisonous chemicals.

4 . Human beings have somehow managed to engineer the night to receive us by filling it with light. This kind of control is no different from the feat ( 壮 举 ) of damming a river. Its benefits come with_________ — called light pollution — whose effects scientists are only now beginning to study. Light pollution is largely the result of bad lighting design. _________ lighting washes out the darkness of night, altering light levels and light rhythms to which many forms of life, including ourselves, have_________. Wherever man-made light spills into the natural world, some aspects of life-migration, reproduction, feeding-is affected.

For most human history, the phrase “light pollution” would have_________. Imagine walking towards London on a moonlit night around 1800, when it was Earth’s most populous city. Nearly a million people lived there, _________ candles, torches and lanterns, as they always had. Only a few houses were lit by gas, and there would be no public gaslights in the streets or squares for another seven years. From a few miles away, you would have been more likely to_________ London than to see its dim collective glow.

We’ve lit up the night as if it were a(n) _________ country. As a matter of fact, among mammals (哺乳动物) alone, the number of species active at night is astonishing. Light is a powerful biological force, and on many species it acts as a magnet attracting them to it. The effect is so powerful that scientists speak of songbirds and seabirds being_________ by searchlights on land or by the light from gas flares on marine oil platforms, circling and circling in the thousands until they drop.

It was once thought that light pollution only affected astronomers, who need to see the night sky in all its glorious clarity. Unlike astronomers, most of us may not need a_________ view of the night sky for our work. __________, like most other creatures, we do need darkness. __________ darkness is pointless. It is as essential to maintaining our biological welfare as__________ itself; the price of modifying our internal clockwork means it doesn’t operate as it should, causing various physical discomforts. So fundamental are the regular rhythms of waking and sleep to our being that__________ them is similar to altering our center of gravity.

In a very real sense, light pollution causes us to__________ our true place in the universe, to forget the scale of our being, which is best__________ against the dimensions of a deep night with the Milky Way — the edge of our galaxy — arching overhead.

World leaders at the 5th meeting of the United Nations Environment Assembly (UNEA) agreed that by 2024, they would create and sign a new treaty on plastics. The new treaty would create international laws     1     could help bring plastic waste under control.

Because plastic is useful for so many purposes, it has become a part of nearly all areas of our lives. It’s hard to look anywhere without finding dozens of     2     (object) made of plastic.

The United Nations Environment Program (UNEP) reports that     3     (current) 400 million tons of plastic is produced every year. By 2040, that number is predicted to double. And even though there’s a lot of talk about recycling, only 9% of all the plastic ever     4     ( produce) has been recycled.

Plastic gives off dangerous gases when it’s made and also when it’s burned or buried in the ground. Scientists say plastics are responsible     5     4.5% of the world’s greenhouse gases — the gases that are driving the climate crisis.

Plastic doesn’t “decompose (腐烂)” like natural materials. Instead, it just breaks into smaller and smaller pieces. And as the plastics     6     (fill) our world break down, they create     7     new problem — microplastics.

Microplastics are so tiny that     8     (they) existence is usually ignored. In the past few years, microplastics     9     (find) almost everywhere, from the North pole to Antarctica, from the top of the Earth’s     10     (high) mountain to the deepest point in the sea. They’ve even appeared in the bodies of animals including humans.

7 . Microplastics —   tiny pieces of plastic waste less than five millimetres long that have been degraded by waves, wind and ultraviolet rays — have been discovered in the deepest oceanic trenches and within the stomachs of the organisms that live there, but we have little idea about where the great majority of them end up. More than eight million tonnes of plastic enters our oceans every year, comprising between 80 and 85 percent of all marine trash, but with inadequate data, there are concerns that these figures could be underestimates.

Currently, most of the data we have on microplastics are accidentally captured by research ships, which use plankton nets to collect marine-microorganism samples. However, researchers Christopher Ruf and Madeline Evans from the University of Michigan have discovered an innovative way to identify and track concentrations of microplastics in the ocean.

The technique relies on NASA’s Cyclone Global Navigation Satellite System (CYGNSS), a constellation of eight micro-satellites used to predict hurricanes that calculate wind speeds above the ocean by measuring the roughness of surface waters. As the satellites are continuously recording, Ruf and Evans realised that they collect a great deal of additional data. It was while analysing these data that they noticed some differences-times where the surface of the ocean appeared to be much smoother than it should, given the prevailing wind (盛行风) conditions.

Knowing that water isn’t roughened as much when it contains a lot of floating material, Ruf and Evans identified a pattern that linked areas of unusual smoothness and predicted microplastic distributions. They found that the difference between their measurements, and how much rougher the surface would be if winds of the same speed were blowing across clear water, was “highly correlated with the presence of microplastics, and the degree of the difference also correlated with the concentration of the plastics.”

The research reveals that there are seasonal variations,where the concentrations of microplastics tend to be higher in the summer and lower in the winter in a very clean, periodic way, which Ruf explains mirrors the way in which the ocean circulation changes throughout the year. It also confirms, as was previously thought, that rivers are the main source of ocean microplastics.

Raising awareness of the issue of ocean microplastics among the public and politicians is just one of the researchers’ future aims; they are also in conversation with Duteh non-profit The Ocean Cleanup and Finnish clean-technology specialist Clewat, which are interested in using the information to more efficiently target their trash-collection campaigns.

So far, only one year’s worth of data have been processed since CYGNSS was launched in 2016. By looking at a longer time period, Ruf and Evans aim to determine whether the seasonal pattern is repeatable, and whether the concentration of micmplastics in the ocean is getting worse.

9 . In the deepest dive in a manned submersible(潜水器), US explorer Victor Vescovo spotted and video-recorded a plastic bag and a pile of candy wrappers on the seabed.

His _________ of plastic waste 11.2 kilometers below sea level in the Challenger Deep in the Pacific Ocean, the deepest known point in the Earth’s oceans, means there is _________ on this planet plastic waste cannot reach, _________ it has been found on Mount Qomolangma and in both Arctic and Antarctic waters.

Since the patent(专利) for plastics was _________ in 1907, 8.3 billion tons of plastic products have already been produced, of which 6.3 billion have been poured into oceans _________ processing.

Most of the discarded(丢弃) plastic products _________ in the ocean. In the Pacific Ocean, plastic garbage and other waste have already formed a(n) _________ that’s 1.6 million square kilometers in size. That is the size of Mongolia.

Every year, about 8 million tons of plastic waste flow into the ocean. It is _________ that the total weight of plastic waste will reach 12 _________ tons by 2050, more than the total weight of oceanic fish.

This plastic waste __________ life in the oceans and on the land alike by filling in their stomachs so they cannot eat, or __________ around their bodies so they cannot breathe. It pollutes the __________ and prevents plants’ roots from digging deep into the ground. Plastic micro-particles(微粒) also join the water __________ and enter the bodies of animals, including humans. As humans are at the top of the food __________ , plastic micro-particles accumulate inside our bodies.

We must do something to __________ the situation. Don’t get plastic bags at the supermarket and take your own reusable one __________ . Give up fast delivery lunches and instead cook or go to the restaurant. Get into the __________ of sorting your garbage.

But that’s so much __________ said than done. Environmentalists have been __________ behavioral changes for at least three decades, yet we __________ to use a growing amount of plastic products.

10 . The fertile land of the Nile delta is being eroded (侵蚀) along Egypt’s Mediterranean coast at an astonishing rate, in some parts estimated at 100 metres per year. In the past, land washed away from the coastline by the currents of the Mediterranean Sea used to be replaced by sediment (沉淀物) brought down to the delta by the River Nile, but this is no longer happening.

Up to now, people have blamed this loss of delta land on the two large Aswan dams in the south of Egypt, which hold back almost all of the sediment that used to flow down the river. Before the dams were built, the Nile flowed freely carrying huge quantities of sediment. But when the Aswan dams were constructed to provide electricity and irrigation, and to protect the huge population centre of Cairo from annual flooding and drought, most of the sediment with its natural fertilizer accumulated up above the dam in the southern upstream half of Lake Nasser, instead of passing down to the della.

Now, however, there turns out to be more to the story. It appears that the sediment-free water picks up sand as it erodes the river bed and banks on the 800-kilometre trip to Cairo. Daniel Jean Stanley of the Smithsonian Institute noticed that water samples taken in Cairo indicated that the river sometimes carries more than 850 grams of sediment per cubic metre of water — almost half of what it carried before the dams were built.

International environmental organizations are beginning to pay closer attention to the region, partly because of the problems of erosion and pollution of the Nile delta, but mainly because they fear the impact this situation could have on the whole Mediterranean coastal ecosystem.

But there are no easy solutions. In the immediate future, Stanley believes that one solution would be to make artificial floods to flush out the delta waterways, in the same way that natural floods did before the construction of the dams. He says, however, that in the long term an alternative process such as desalination (脱盐) may have to be used to increase the amount of water available.