A study shows 176 bird species have been found to build nests with human litter, such as plastic bags and fishing nets.     1     worries the scientists is that such materials can harm chicks and even adult birds. The study     2     (review) research covering almost 35,000 nests and finds that birds use human-made materials in nests on all continents except Antarctica. While such behaviour     3     (observe) as early as in the 1830s, in recent years it has undoubtedly increased.

There are     1     (vary) causes of water pollution. Large amounts of industrial waste poison the water after they enter water bodies. Moreover, animal and human waste pollutes the water. Water pollution is also caused by     2     (poison) chemicals used in agriculture.

    3     (pollute) water bodies not only do harm to animals and plants; they also have a long-lasting effect     4     humans. For example, in many parts of the world, the poor quality of the local     5     (drink) water gives rise     6     public health problems.

    7     (prevent) further damage     8     water bodies, it is necessary to take some measures. First, we must draw public attention     9    the problem. Second, more strict laws should    10     (pass) to help reduce water pollution. Third, we can volunteer to take part in clean-up activities.

The color of the ocean has changed     1     (great) recently and human-caused climate change is responsible, according to     2     new study.

More than 56% of the world’s oceans have changed color,     3     cannot be explained, said a team of researchers, led by scientists from the National Oceanography Center in the UK.

Tropical (热带的) oceans close to the equator     4     (become) greener in the last 20 years, according to the study     5     (publish) in the journal Nature.

“    6     is not clear exactly how these ecosystems are changing”, said Stephanie from the Center for Global Change Science. “All changes are causing an imbalance in the natural organization of ecosystems. Such imbalance will only get     7     (bad) over time if our oceans keep heating,” she told CNN.

Though the researchers are still working to understand exactly     8     the changes mean, they said what is clear is that the changes are being driven     9     human behavior.

The researchers studied changes in ocean color from space by     10     (watch) how much green or blue light is reflected from the surface of the sea.

Glass recycling has become such a big industry that the amount of glass     1     (recycle) is not meeting the demand for new glass to be produced. Some states in U. S. have attempted to resolve this situation in hopes of encouraging the     2     (produce) of glass over plastic by offering monetary incentives (奖励) for glass. For example, California has a special program     3     you can earn five cents for most glass bottles as well as plastic ones and aluminum cans less than 24 ounces. For items over 24 ounces, you can earn 10 cents each.

The conch (海螺) is       1     (wide) considered to be the national dish of the Bahamas. Queen conch is one of important food materials and can live for 30 years.

Conches can be very     2     (expense) in the U.S. and other places. But it is so common in the Bahamas     3     it can often be found in meals costing     4    (little) than two     5     (five) of the population in rural (农村的) parts of the Bahamas eats conches weekly. The country of about 400,000 is home     6     9,000 conch fishers-around two percent of the population. This number appears to be holding steady even as conches decrease (减少) in number. For many fishers here, fishing is both a family tradition     7     a path to middle class life. The meat of the conch     8     (be) worth millions of dollars per year, and it also helps increase tourism to     9     islands.

The conch is one example of the threat (威胁) overfishing presents to traditional foods around the world. Similar problems     10     (see) in Senegal now, where overfishing has taken away white grouper. The fish has long been the basis for the national dish of thieboudienne.