Answer:
dear user nitrogen fixation is so important bcoz of the reasons given above
For the first question the answer is C the second one the answer is A
One very specific way that humans caused changes in the atmospheric CO2 levels is the fossil fuels that the humans are burning is causing an increase in the CO2 levels. Other ways humans are doing this is by driving cars, deforestation, and an increased industrialization that releases CO2 into the atmosphere.
B. A b and d are eukaryotic
48 because u have to look at it on the textbook