The answer is a. Nitrogen
A forest station can be a base in a forest where people monitors different biological aspects, like the fauna and the flora of their interest. For example, a forest station can be useful for monitorin endangered species.
A. Natural Selection. This is because the weeds that are not resistant to it die out before they can reproduce, but the resistant ones grow to maturity and then reproduce, passing down the resistance gene. Over time, the resistance gene would become a normal thing in weeds, while the non-resistant gene would not exist anyone, since the gene could not be passed on.
1. A
2. A
3. C
I hope this helps:)
