...the rural calm of Grand Rapids, Michigan.密歇根州大急流城田园般的宁静What is needed in such cases is a calm appraisal of the situation...在此类情况下需要对形势有一个冷静的评估。Seals basked on boulders in a flat calm.海面风平浪静，海豹在巨石上晒太阳。The river is glas...
苗条的天鹅和纤细的臭鼬在滑滑的黏泥上游泳.Slim swans and slender skunks swim in the slippery slime.而循环冷却水系统生物黏泥的产生主要是因系统发生漏油事故所致.And the main reason to bring biological sludge into circulating water system is oil - leaking accident....