Microplastics (微塑料) are small pieces of plastic that enter and pollute the environment. Microplastics are not a specific kind of plastic, but any type of plastic piece that is less than five millimeters (毫米) in length.

    The team, from South Korea's Incheon National University and Greenpeace East Asia, examined 39 brands of salt from 2l countries. Of these, 28 were sea salt, 9 were rock salt, and 2 were lake salt. Microplastics were not found in three of the samples (样品) : refined (精制的) sea salt from Taiwan, China, refined rock salt from Chinese mainland, and unrefined sea salt in France. Salt made in Asia had by far the most microplastics of all the samples, which has to do with where plastic most often enters the ocean. Nine of the top 10 sea salt are sampled with the highest amount of microplastics that come from Asia.

    Actually, microplastics are everywhere. Sea salt and lake salt are made by evaporating (蒸发) water and getting the salt that remains. Plastic waste comes into the bodies of water from rivers, so it's no surprise to find microplastics in salt. Scientists have been finding microplastics in salt for years, including in salt from countries in Asia, Europe, and Africa. But the latest study goes a step further, finding that looking at where the salt was produced is a good way to find how much plastic pollution is in that country.

    According to their results, the researchers said that an adult ingests (摄入) about 2,000 pieces of microplastics in salt per year. But microplastics in salt amount to about 6%of a person's total microplastics ingestion. Microplastics have also been found in water, fish and both indoor and outdoor air. All together, an adult ingests over 32,000 pieces of microplastics per year. 80% of them come into our bodies with the air.

    It's almost impossible for humans to avoid microplastic pollution.

    The environment in our city is becoming worse and worse. We can see rubbish everywhere. Even theof the river is full of rubbish. This turns our beautiful city into a(n)one. As a citizen, we should do something we can to help the environment. First, don'teverywhere. We should put rubbish into rubbish. In this way we can keep our city clean. Second, we shouldn'twaste paper. Instead, we should collect it so that it can be. When buying takeaway food, don't usebags or one-off chopsticks. It's a good way to help reduce rubbish. Third, we can save energy bythe lights when leaving the room., everyone can do something to make a difference.now!

—_________. People should use public transportation more often.

    Each one of us shares this planet with seven billion others. And we all need1. People and products need to move from city to city and country to country. However, we all know2most cars, motorcycles, boats and planes cause air pollution. They are also3. This is a serious problem in many cities.4inventors are coming up with creative ideas to try to reduce the pollution and noise.

    In many cities around the world, motorcycles are very5. Now Vietnam has many motorcycles. Motorcycles are a faster and cheaper way to get around a city than6. Yet air pollution is a growing problem. In large cities, people7it is difficult to breathe. To solve these problems, a US company designed an environmentally friendly motorcycle. It uses electricity as fuel (燃料) . As a result, there is8pollution. It's also quiet and fast. This makes9a good choice for getting around a city.

    Venice is a city with only a few10. There are no cars in the city center.11cars, water taxis and buses carry people along the city's canals (运河) . However, they cause pollution, 12for the water. English engineers Dick and Jem designed a solar-powered (太阳能的) water taxi. The water taxi13run for a day after being charged (充电) .

    Planes also cause air and noise pollution. Designing an environmentally friendly airplane is a real14. Some airplane companies have15to solve the problems. Swiss engineers have gone one step further. They developed a solar airplane. This plane holds the world record for the longest solar-powered flight—1,541 kilometers from Arizona to Texas in America.