问答题 翻译：The gas saturation is obtained in the same manner as the retort.

问答题 翻译：These reservoirs can be classified according to rock types, depending on variations in source rock, transport distance, and depositional environment.

问答题 翻译：Classification of traps logically falls into three broad general groups: (1) structural, (2)stratigraphic, and (3)combination.