A) what two processes account for adding free oxygen to the precambrian atmosphere? b) what do we mean by free oxygen, and c) which of these two processes were most important?

Adeveloping nation's economy is based on a developed nation's economy is based on stay tuned- i may post some more questions from my study guide : )

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.

What weather system might be occurring if the pressure gradient decreases and fish harvests in peru are weaker than normal