When it comes to traveling in China’s Guangxi Zhuang Autonomous Region, the Li River is one of the destinations tourists won’t miss. However, with the number of tourists increasing, the river’s water     1    (pollute). Some tourists     2    (frequent) threw garbage into the river. Kitchens on the tour boats were using lots of oil,     3     was often thrown into the water. Besides, more chemicals were used       4    (increase) crop production,    5    (cause) water quality issues and a decrease in the number of fish species. These problems made the local officials worried about the natural environment. They felt     6     urgent to take action to restore the river’s original beauty.

The waste water treatment facilities have been constructed, which has helped improve the water quality and water     7    (conserve).     8    (dozen) of polluting enterprises were closed or moved. What’s more, the local government set up strict regulations regarding further industrial development. So far new rules have been introduced regarding tour boat routes and garbage disposal methods. With these measures, it is believed that the beauty of the Li River will come back soon.

What is the most amazing is that the “Water Ten Plan” is now tackling water pollution across the country. With such campaigns     9     effect, China’s waterways are heading towards a clean and     10    (sustain) future.

3 . 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.

5 . 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.”

6 . A new analysis of photographs from the International Space Station has identified a shift in the kind of lighting technologies that European countries are using at night to brighten streets and buildings. Researchers have found that the old warm high-pressure street lights are rapidly being replaced by cooler LED lights. The University of Exeter study, published in Science Advances, claimed that “this phenomenon is widely increasing the risk of harmful effects to ecosystems”.

LED lighting was promoted as being intended to reduce emissions, but its usage has raised energy consumption. One explanation of this is that the increase in power efficiency and the associated decrease in economic cost have driven increased demand for lighting, therefore, any efficiency gains have been counteracted by increased consumption of light.

The study also claimed that previous research into the effects of light pollution have underestimated the impacts of blue light radiation. Chief among the health consequences of blue light is its ability to reduce the production of melatonin(褪黑素)that regulates sleep patterns in humans and other organisms. Scientific studies have warned that increased exposure to artificial blue light can worsen people’s sleeping habits.

The increase in blue light radiation in Europe has also reduced the visibility of stars in the night sky, which may have impacts on people’s sense of nature. Blue light can also alter the behavioral patterns of animals including bats and moths, as it can change their movements towards or away from light sources.

David Smith, of the conservation charity Buglife, said, “Light pollution can dramatically impact animals. We should consider light from a wider biological perspective than that of just humans and focus on better quality lighting that is harmonious with our natural world. Better quality and lower levels of lighting would help save energy, and lower financial costs, while also making our environment safer for living beings. Authorities can dim the lights during night hours, and change the bandwidths(带宽值)of their LED bulbs to produce less harmful blue light.”

My aim in life is     1     (protect) the environment for future generations. I want to become     2     environmental consultant after graduation. Many people think that pollution cannot     3     (stop) if we want the country to develop. But that is not true. We can cut back on     4     (danger) and dirty waste from factories. Although a factory produces a large quantity of goods, it does not mean that it has to pump a lot of pollution into the environment. I also want to teach people to buy products     5     have been recycled. This is much     6     (good) for the environment, because it means we do not need to cut down many trees.Companies and businesses can still operate,     7     the Earth will not have to suffer.

There is no     8     (debate) that we also have a problem with population. The number of people in the world keeps growing, and we    9     (produce) more rubbish and using up more raw materials. What if they run out? I am confident that if we are all willing     10     (work) together, we can overcome these challenges and keep the Earth clean and healthy.

8 . We all have an idea about the common types of environmental problems. However, light pollution may be a new term to many of us. But, the fact is that it does affect mankind, other living forms and the environment as a whole.

What is light pollution? It presents all forms of misused man-made light. The obvious cause of light pollution is the use of outdoor lighting products improperly. It can be office lighting, car headlights, station lights, streetlights and many more.

Light pollution is harmful to both animals and plants. Upon studies, it is found that obvious effects are observed in the behaviour of animals that are active at night. Needless to mention, bright light at night makes it difficult for these animals to hunt, wander and perform their regular activities. Light pollution is directly or indirectly responsible for causing several diseases. Its effects are related to disturbance in the physical rhythm (节奏). It contributes to risks of developing cancerous cells. So, it’s nothing less than a threat to human health.

You have already seen the negative effects of light pollution on animals and human health. Apart from this, the actual cost of misused light is about millions of dollars every year. It also leads to the release of greenhouse gases and global warming. After all, coal or gas is used for producing electricity.

While outdoor lighting and using man-made lighting products are part of our modern lifestyle, some simple ways will surely help in reducing light pollution. For example, while installing (安装) outdoor lighting, make sure that they are pointed downwards. Also, use only the required lighting equipment for both home and offices. Believe it or not, many people living in the urban areas cannot view clear sky and stars at night. Let’s contribute our part in reducing the pollution.