Which of the following does not affect a population's size?
a. birth rate
c. death rate
b. exchange rate
d. migration rate

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.

Can someone me? i need to have this done as soon as possible! i'm putting 20 points on this!

Which of the following can scientists estimate geologic time? a.observing rock sequences b.radiometric dating c.comparing fossils d.all of these