How can a river or a lake catch on fire?- If there is oil or oil-soaked debris in the water and the get ignited a river or lake can catch on fire. A great example of this would be the Cuyahoga River, as it caught on fire several times throughout the years.
What lake do you think people could pollute quickly?- Lake Erie because it is relatively small and less shallow than other lakes.
Give two examples of point source pollution?- Examples would include smokestacks, discharge pipes, and drainage ditches. Factories and power plants can be a source of point-source pollution, affecting both air and water.
Hope this helps! :)