Pea plants
These belong to legumes and legumes have a mutualistic relationship relationship with bacteria which allows them to add atmospheric nitrogen into the soil by a process called nitrogen fixation.<span />
Answer:
I would believe the mesosphere would be the most difficult layer to breathe. Troposphere is where we are, ov we can breathe here, stratosphere would be hard to breath in as well
<span>a and c could be true
Animals don't have peace treaties with each other and the other two options would both allow a population to increase in size.</span>
the main human activity is air pollution
