Any suggestions for learning biology info for test? all ideas welcome

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

What type of pollution does household garbage cause

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above