Im confused can someone assist me ?

Which are forms of nitrogen that are usable by humans

If the birth rate of a population of dolphins is 2.0, the death rate is 0.5, and the population size is 100, what is this dolphin's population growth?

What is a universal way that predation benefits the predator? predation increases mate availability. predation in defense of space. the predator gets the energy it needs to survive. the predator keeps parasites from hurting the species.