简答题 翻译：Also specified in gas purchase contracts is the maximum amount of sulfur the sales gas may contain.

翻译In general, gas pipelines operate at higher pressure than crude lines; gas is moved through a gas pipeline by compressors rather than by pumps; and path of natural gas to the user is more direct. 点击查看答案

翻译：the pressure of a gas varies inversely as its volume, with temperature being constant. 点击查看答案