Which of these organisms is a part of the group that produces all of the available energy in a food web?
a. fly
b. grass
c. mouse
d. sun

According to the earth science reference tables, during which geologic time period were the continents of north america, south america, and africa closest together?

All of the following statements about the biosphere are true except: a. light and heat from the sun do not affect the biosphere. b. the biosphere gets resources from earth's crust, hydrosphere and atmosphere. c. like "biology", the name for the biosphere comes from the greek word for life. d. the biosphere includes all living organisms on earth's surface.

The world wars of the twentieth century immediately led to a. the establishment of a communist bloc in eastern europe b. the urbanization of europe’s societies c. an emphasis on humanism d. an emphasis on ties to greek and roman societies select the best answer from the choices provided. a b c d