Đề thi thử THPT Quốc gia môn Tiếng Anh năm 2016 trường THPT Võ Văn Kiệt

No one can calculate the quantity of solid waste that has been dumped in the world’s oceans, but the total certainly exceeds many millions of tons. For example, from 1880 to 1895, 75 percent of the solid waste from New York City was dumped untreated into the Atlantic Ocean. Although it is now prohibited by law, the dumping of solid waste, including wastewater sludge, industrial waste, and high-level radioactive waste were common in the United States until 1970. Cruise ships and huge floating fishing factories still regularly dispose of their solid waste products directly into the ocean.

The earth naturally recycles water and refreshes the land in what is called the hydrological cycle. The hydrological cycle not only renews the supply of water, but cleans it as well. The process begins as heat from the sun causes sea water, 97 percent of the earth’s total water reserve, to evaporate and form clouds. Because water evaporates at lower temperatures than most pollutants, the water vapor that rises from the seas is relatively pure and free of the contaminants, which are left behind. Next, water returns to us as rain, which drains into streams and rivers and rushes toward the sea.

Chemicals, petroleum products, and other dangerous substances such as radioactive materials remain in the ocean, polluting it permanently. The polluted ocean water kills fish or makes them dangerous to eat, posing health problems for those who consume them. It kills the tiny sea creatures that are the source of food for larger fish, sharks, and whales. It also spoils a source of great beauty and pleasure when some solid waste is thrown onto beaches during storms. Discharged petroleum products are frequently found on beaches and they not only ruin the beach, the petroleum residue kills hundreds of shore birds. Nonpoint pollutants are dumped into lakes, rivers, and streams that may be far away from any ocean. However, these pollutants flow, eventually, into the oceans. They can come from a variety of sources, from road salt to agricultural pesticides. One source of nonpoint pollution is runoff from farming, including fertilizers, manure, and pesticides. Another source is industrial runoff, including heavy metals, phosphorous, and many other chemicals. Urban runoff (oils, salts, various chemicals) and atmospheric fallout of airborne pollution are other sources of nonpoint pollutants that reach the oceans. This includes water and waste from sinks, toilets, washing machines and bathtubs. The problem with this type of waste is that it provides massive amounts of nutrients for water plants such as algae, so that they grow rapidly. This sudden growth causes concentration or algae blooms, which use up the oxygen in the water. As the oxygen level of the water declines, many organisms suffer and die, and the ocean ecosystem is radically altered. This can be prevented by the installation of waste treatment plants that prevent waste from entering the sea, but such facilities do not exist in many poorer countries.

Sharks have gained an unfair reputation for being fierce predators of large sea animals. Humanity’s unfounded fear and hatred of these ancient creatures is leading to a worldwide slaughter that may result in the extinction of many coastal shark species. The shark is the victim of a warpedattitude of wildlife protection; we strive only to protect the beautiful, non- threatening parts of our environment. And, in our efforts to restore only non- threatening parts of our earth, we ignore the other important parts.

A perfect illustration of this attitude is the contrasting attitude toward another large sea animal, the dolphin. During the 1980s, the environmentalists in the U.S protested the use of driftnets for tuna fishing in the Pacific Ocean since these nets also caught dolphins. The environmentalists generatedenough political and economic pressure to prevent tuna companies from buying tuna that had been caught in driftnets. In contrast to this effort on behalf of the dolphins, these same environmentalists have done very little to help save the Pacific Ocean sharks whose population has decreased nearly to the point of extinction. Sharks are among the oldest creatures on earth, having survived in the seas for more than 350 million years. They are extremely efficient animals, feeding on wounded or dying animals, thus performing an important role in nature of weeding out the weaker animals in a species. Just the fact that species such as the Great white Shark have managed to live in the oceans for so many millions of years is enough proof of their efficiency and adaptability to changing environments. It is time for us humans, who may not survive another 1, 000 years at the rate we are damaging the planet, to dispel our fears and begin considering the protection of sharks as an important part of a program for protection of all our natural environment.