One type of recycling, called downcycling, involves repurposing a material into a new product of lesser quality. It can include varying grades of plastic, paper products, and other materials.

Downeycling     1     (know) as downstream recycling. It is most common in terms of     2     (industry) materials. These products lose their value as they are recycled,     3     limits their capacity for new use. Their recycled form is typically both weaker and cheaper     4     their original one. White writing paper, for example, is often downcycled into cardboard; once downcycled to this new form, it can no longer be used as white paper again.

    5     (give) products a new life is considered a good way to reuse materials and avoid waste. Once downcycled to their full capacity however, these materials are eventually so degraded that they cannot be reused further. Since downcycled products are considered of lower quality than their original form, they cannot be used in remaking their original product.

Products are provided with codes     6     (determine) their grades and whether or not they may be recycled. Plastic, glass, and aluminium products     7     (code) with the number one may be remade into something     8     equal or greater value. This type of recycling is known as upcycling, and represents the forward compatibility of recycled components.

Items available for downcycling often require additional chemicals, energy,     9     other treatments in order to transform them into something usable. Durable plastic products in particular require much additional treatment. Trash bins, tables, and chairs are also considered materials with     10     high energy cost to recycle.

In the past few years, scientists have found microplastics in our soil, tap water, bottled water, beer and even in the air we breathe. And there’s growing concern about the potential health risks they pose     1    humans.

The new analysis in the UK have discovered microplastics widely distributed across all 10 lakes and rivers sampled. More than 1,000 small pieces of plastic per litre were found in the River Tame, which was revealed last year as    2     (pollute) place tested worldwide. Even in relatively remote places such as the Falls of Dochart and Loch Lomond in Scotland, two or three pieces per litre were found.

Microplastics are not a specific kind of plastic, but rather any type of small pieces of plastic    3     is less than 5 mm in length according to the U.S. National Oceanic and Atmospheric Administration. They    4    originate from a variety of sources, including cosmetics, clothing, and industrial processes.

Humans are known to consume the tiny plastic particles through food and water, but the possible health effects on people and ecosystems have yet    5     (determine). One study, in Singapore, has found that microplastics can harbor harmful microbes.

Research by the National University of Singapore found more than 400 types of bacteria on 275 pieces of microplastic    6     (collect) from local beaches.     7     included insects that cause gastroenteritis (肠胃炎) and wound infections in humans.

“Microplastics    8     (find) absolutely everywhere now but we do not know the harm they could be doing,” said Christian Dunn at Bangor University, Wales, who led the work. “It’s no use    9     (look) back in 20 years’ time and saying: ‘If only we’d realized just how bad it was.’ We need to be monitoring our waters now and we need to think, as a country and a world,     10     we can be reducing our reliance on plastic.”

People release (放开) balloons for special occasions like memorial services and grand openings. It is fun and exciting. But it really causes great destruction to the environment and threatens the     1     (life) of wildlife.

When a balloon flies into the sky, it doesn't end up     2     (stay) there. It eventually bursts and returns to the earth as ugly litter. Balloons can even travel thousands of miles and pollute the most remote and pure places. More     3     (sad), they can present a threat to many animals. Birds, whales, turtles and other animals often mistake balloons     4     food, which can do damage to them because balloons contain     5     (harm) chemicals. Balloons even kill animals. When an animal swallows a balloon, it can block     6     (it) intestinal tract (肠道), resulting in starvation.

Part of the reason why releasing balloons     7     (permit) in so many places is that some balloons do break down eventually. However, it takes about four years     8     (break) down completely.

Watching hundreds of balloons slowly going up into the sky might give you a five-second thrill,     9     is it worth a bunch of dead animals and so many places full of rubbish? Absolutely not.     10     we should do is to get creative and come up with alternative ways to celebrate.

Most gardeners will probably say gardening     1     (be) good for you. According to a study, people who garden have a     2     (healthy) diet, get more exercise, and feel less stress. Researchers studied the benefits of gardening in shared community gardens     3     people work together. They suggest gardening may reduce stress because it exposes people to nature, while community gardens also provide     4     (chance) for social interaction. Therefore, they hope the results will encourage doctors and government leaders to regard community gardens as a vital part of the public health system.