1 . Most environmental pollution on Earth comes from humans and their inventions, such as cars or plastic. Today, car emissions(排放物) area major source of air pollution leading to climate change, and plastics fill our ocean, creating a significant health issue to marine(海洋的) animals.

And what about the electric light, thought to be one of the greatest human inventions of all time? Electric light can be a beautiful thing, guiding us home when the sun goes down，keeping us safe and making our homes bright. However, like carbon dioxide emissions and plastic, too much of a good thing has started to impact the environment. Light pollution, the inappropriate use of outdoor light, is affecting human health, wildlife behavior and our ability to observe stars.

Light pollution is a global issue. This became obvious when the World Atlas of Artificial Night Sky Brightness, a computer-generated map based on thousands of satellite photos, was published in 2016. Available online for viewing, the map shows how and where our globe is lit up at night. Vast areas of North America, Europe, the Middle East and Asia are glowing(发光) with light, while only the most remote regions on Earth(Greenland, Central African Republic and Niue) are in total darkness. Some of the most light-polluted countries in the world are Singapore, Qatar, and Kuwait.

Sky glow is the brightening of the night sky, mostly over cities, due to the electric lights of cars, street lamps, offices, factories, outdoor advertising, and buildings, turning night into day for people who work and play long after sunset.

People living in cities with high levels of sky glow have a hard time seeing more than a handful of stars at night. Astronomers are particularly concerned with sky glow pollution as it reduces their ability to view stars.

More than 80 percent of the world’s population, and 99 percent of Americans and Europeans, live under sky glow.

6 . To solve a big environmental problem, chemists have been thinking small. Really small: a new mini robot with the purpose of helping clean up tiny plastic that pollutes water across the world.

The new microrobots, each of which is no bigger than the tip of a pencil, are magnetic(有磁性的)and shaped like four-pointed stars. When the sunlight shines on them, they can swim in a direction; when the sunlight disappears, they stop moving. Finding a piece of plastic, they hold onto it, produce chemical reactions and start to break it down.

The project is led by chemist Martin Pumera, a researcher who also studies ways to build microrobots at the Czech University of Chemistry and Technology in Prague. About ten years ago, he noticed the microplastic was everywhere, from the bottom of the ocean to the ice on the top of mountains. It even turned up in drinking water, both bottled and tap water. Just think about how much plastic you meet every day. It doesn’t easily degrade ( 降 解 ) which is a big problem. Therefore, Pumera chose to focus on the problem of water pollution caused by microplastic.

The researchers tested the microrobots on four types of plastic in the lab. After a week, all four began degrading, losing around 3 percent of their weight, which showed the microrobots were breaking the plastic down. The robots also turned the plastic’s smooth surface into the rough one. Finally, the scientists showed that magnets could attract the microrobots at the end of the test - along with the plastic waste.

In fact, Pumera says they still have a long way to go. These microrobots are unlikely to succeed in degrading all types of plastic. They’ll also need a lot of testing to show that they’re safe in open waterways, such as at sea. But he thinks that these challenges can be overcome. Someday, the microrobots will play a big role in a worldwide cleanup effort.

7 . The world itself is becoming much smaller by using modern traffic and modern communication means. Life today is much easier than it was hundreds of years ago, but it has brought new problems. One of the biggest problems is pollution. To pollute means to make things dirty. Pollution comes in many ways. We see it, smell it, drink it and even hear it.

Man has been polluting the earth. The more people, the more pollution. Many years ago, the problem was not so serious because there were not so many people. When the land was used up or the river was dirty in one place, man moved to another place. But this is no longer true.

Man is now slowly polluting the whole world.

Air pollution is still the most serious. It’s bad for all living things in the world, but it is not the only one kind of pollution. Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us angry more easily.

Many countries are making rules to fight pollution. They stop people from burning coal in houses and factories in the city, and from putting dirty smoke into the air. Pollution by SO₂ is now the most dangerous kind of air pollution. It is caused by heavy traffic. We are sure that if there are fewer people driving, there will be less air pollution.

The earth is our home. We must take care of it. That means keeping the land, water and air clean. And we must take care of the rise in pollution at the same time.

Japan said     1     Tuesday that it had decided to     2     (gradual) release tons of treated wastewater from the ruined Fukushima Daiichi nuclear plant (福岛第一核电站) into the ocean,     3     (describe) it as the best solution for dealing with the leftovers (残留物) from the Fukushima nuclear accident, one of the     4     (serious) in the world.

The decision ends years of debate over how to deal with the water,     5     is enough to fill more than 500. Olympic-sized swimming pools. “The Japanese government ignores concerns and strong opposition     6     at home and abroad. Such     7     irresponsible act not only directly harms the interests of the people in Japan’s neighboring countries,     8     threatens the global marine environment and international public health     9     (secure),” Chinese Foreign Ministry spokesman Wang Wenbin said,

Greenpeace criticized Japan’s plan and said there are other solutions that should     10     (consider). “Rather than using the best available technology to store and process the water over the long term, they have chosen the cheapest solution, dumping the water into the Pacific Ocean.” the group said.

10 . The amount of plastic pollution in the oceans is rapidly increasing. This is problematic, as at least 700 species of sea animals — including sharks, whales seabirds and turtles — can be trapped in the stuff or mistake it for a tasty snack. While we know that some species seem to eat plastic because it looks like jellyfish or some other food source, less research has been carried out into what sea plastic smells like to sea animals.

But now, a study from the University of North Carolina at Chapel Hill has found that the coating of algae and microbes (藻类、微生物) that naturally builds up on ocean plastics causes the rubbish to give off the smell of food.

The researchers took 15 healthy turtles, each around five months old and placed them in a laboratory aquarium (水族箱). They then piped in clean water, clean plastic, turtle food, and plastic that had been down in the sea environment for five weeks. The turtles showed no reaction to the smell of clean water or clean plastic. But when they were exposed to the smells of ocean plastic or turtle food, they exhibited hunting behaviour — like sticking their noses out of the water and showing increased activity.

“This finding is important because it’s the first demonstration that the smell of ocean plastics causes animals to eat them,” said Dr Kenneth J Lohmann, who took part in the study.

“It’s common to find the sea turtles with their digestive systems fully or partially blocked because they’ve eaten plastic materials There also are increasing reports of sea turtles that have been ill and stranded on the beach due to their swallow of plastic.”

“Once these plastics are in the ocean we don’t have a good way to remove them or prevent them from smelling like food” said Lohmann. “The best thing we can do is to keep plastic from getting into the ocean at all.”