Which of the following is an example of microevolution? A. The formation of four new species of fish in a lake over thousands of years
B. A mass extinction that occurs because of major environmental changes in a habitat
C. A change in the frequency of body color in species of beetle over time
D. The formation of two new species of rodent that have been isolated by a mountain range

Waste water from industries and domestic sources can be treated by chlorination or ultraviolet radiation. there are pros and cons to using either chlorine or uv radiation to kill harmful microorganisms. what is one reason chlorination would be preferred over ultraviolet radiation? a) chlorine only eliminates visible impurities and is ineffective against microorganisms. b) chlorine not only kills bacteria but provides a residual effect on returning microorganisms. c) uv radiation can be used only to treat drinking water and is ineffective in treating waste water. d) ultraviolet radiation is more effective