Câu hỏi:

VII. Read the passage, and choose the correct answer A, B, C or D for each question.

HOW TO STOP WATER POLLUTION

Water pollution is one of the biggest threats to the environment today. There are several sources of water pollution ranging from sewage and fertilizers to soil erosion. The impact of water pollution on wildlife and their natural habitats can be immense. There are also a number of things that the average person can do to help stop water pollution.

We should conserve the soil because soil conservation influences water pollution through erosion. As soil is eroded by water, it transfers sediment from the land to the body of water, which is polluted by the chemicals in the sediment. Phosphorus and industrial chemicals can be pulled into water through soil erosion. When phosphorus levels in water become too high, they can lead to algae blooms that can cause massive fish deaths and make water unsafe for human use. The best way to prevent soil erosion is to keep the banks of rivers well-covered with plants or trees. Planting trees can have a significantly positive impact on the reduction in soil erosion.

The oil used to lubricate engines in all types of machines needs to be changed regularly. When the oil is changed, it presents a number of environmental hazards if not disposed of properly. When a leaky engine releases this oil into the street, it runs to the sewer and makes its way into waterways.

Wherever you see a lot of human recreation, you will almost always see lots of evidence of human use. Wrappers, bottles and other trash are unfortunately a common site at many well-used beaches and rivers around the world. It should be fairly obvious that the trash from these places often ends up in waterways and can cause pollution. Plastics are an especially big issue when it comes to water contamination at beaches and waterways. Picking up litter wherever you find it is honestly the best, fastest way to do your part to stop this type of water pollution.

Organize cleaning parties with local people to make the reach larger. Get businesses involved as sponsors who will donate prizes to the person who collects the most trash if you're having a hard time finding people to sign up to help.

It is estimated that the consumption of plastic by humans is between 250 and 300 million tons a year. About 80% of the plastic in the oceans came from the land. Using alternatives to plastics or using “less disposable” plastics whenever possible can have a surprising impact on ocean pollution. The fact that plastic is cheap and useful for different purposes makes it obvious choices for many people.

Lubricants can cause environmental hazards when ______________.