Sludge banks are formed if sewage is disposed of in A. Rivers B. Seas C. Lakes D. None of these

The correct answer is: A. Rivers

Sludge banks are formed when sewage is disposed of in rivers. Sewage is a mixture of human waste, industrial waste, and stormwater runoff. When sewage is dumped into a river, it can cause a number of problems, including:

• Pollution of the river water. Sewage contains harmful bacteria and viruses that can make people sick if they come into contact with the water.
• Degradation of the river ecosystem. Sewage can kill fish and other aquatic life, and it can also damage the river’s banks and shoreline.
• Sludge banks. When sewage is not properly treated, it can settle out of the water and form sludge banks. These sludge banks can block the flow of the river, and they can also be a breeding ground for mosquitoes and other pests.

To prevent sludge banks from forming, it is important to treat sewage properly before it is released into rivers. Sewage treatment plants remove harmful bacteria and viruses from the sewage, and they also help to remove solid waste. Properly treated sewage can then be safely released into rivers without causing any harm to the environment.

Option B, seas, is incorrect because sludge