Oxygen is transported by to the where it is used to break down the into water, carbon dioxide, and usable energy. cells
heart
sugar
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How did the research presented in the article affect scientists' understanding of the evolution of eukaryotes

What have we learned from fossil evidence about evolution? a) it is an abrupt change. b)the process is observable. c) it takes place during one lifetime only. d)the most complex traits are always selected.

9. wind power creates pollution. water air soil noise