E) In the laboratory, two species with identical niches are especially easy to maintain in a mixed culture C) many, small offspring D) All of the choices are correct. B) oscillations in population size that remain of constant amplitude through time. Solution E) In the laboratory, two species with identical niches are especially easy to maintain in a mixed culture C) many, small offspring D) All of the choices are correct. B) oscillations in population size that remain of constant amplitude through time..