常见例句用作名词 (n.)This was the result from the large-scale regression in the Late Ordovician.这是奥陶纪晚期大规模海退的结果。Major hydrocarbon source rocks are in the Cambrian and Ordovician.寒武-奥陶系烃源岩是该区主力烃源岩; 返回 Ordovician