How do we know that oxygen was present in the Archean time period?

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

The diagram shows , , and . which statement can be proven true from the diagram? a. ∠dgb is supplementary to ∠ega. b. ∠dgb is supplementary to ∠cgb. c. ∠cgb is supplementary to ∠agd. d. ∠ega is supplementary to ∠egc. e. ∠egd is supplementary to ∠cgb.

How do you think the different landforms of northern and southern europe would affect ways of life in those two areas