3.This paper made a study of the variety regulation of pathogens in the activated sludge through biological fermentation using Aspergillus niger as zymophyte.
10.Pigeons are often seen as dirty birds and an urban nuisance, but they are just the latest in a long line of animals that have been found to have abilities to help humans.
11.In places like New York and Chicago, these thousands of overhanging wires not only destroyed the attractiveness of the thoroughfare, but constantly interfered with the fire department and proved to be public nuisances in other ways.