Which of the following is a cause of eutrophication of a lake?
a. a high rate of evaporation causes salt accumulation. b. floodwater deposits a large amount of sediment. c. excess nutrients promote the growth of algae.
d. water begins to collect in a low-lying basin.

If we represent the solar system on a scale that allows us to walk from the sun to pluto in a few minutes, then a) the planets are microscopic and the stars are millions of miles away. b) the planets are the size of basketballs and the nearest stars are a few miles away. c) the planets are marble size or smaller and the nearest stars are thousands of miles away.

Many areas surrounding the caspian sea contain important a. rare minerals b. forestry resources c. gold and silver mines d. oil and natural gas fields

Following lenins death, who took control of the soviet union