From plants because they give off oxygen so EVERYWHERE
Due to decreased light penetration, B. THE MOUTH of the rivers and streams will have less diversity of plant life.
The decreased light penetration is brought about by the murkiness of the water due to numerous deposits of sediments. Sediments that have been collected at the water travels towards the mouth of the rivers and streams causes the water to be muddy and murky making it impossible for light to penetrate.
Many factors have contributed to increase in life expectancy. Examples such as medical advancements in modern medicine, less wars being fought, improvement in sanitation, eating a healthy diet, a overall healthier lifestyle (for example, people don’t smoke cigarettes as much as the olden days) and easier access to education.
A. Silt is no longer carried down river.