Definitely smoking. That’s the prime cause of lung cancer.
Point source means: the pollution that comes from a single point (examples)
Sewage pipes releasing sewage into a ditch
Smokestack style factory chimneys
Oil pipes
Pollution which is caused by rain fall or snow melting into the ground. As the runoff moves, it picks up and carries away natural and human made pollutants, Finally reaching a lake, river, ocean, groundwater.
That's a very good question!! That would have to go along with the process of weathering and erosion. Basically how the heat, weather, and he pressure of the Earth forms land . Mount Everest was formed when India plate moved rapidly northwards towards Euro Asia plate.
Hope this helps!!
