Some questioned if the natural gas systems that heated schools was to blame.

一些人质疑，为学校供暖的天然气系统是否应该受到指责。

Landfills are the third-largest source of methane emissions worldwide, after oil and gas systems and agriculture.

垃圾填埋场是全球甲烷排放的第三大来源，仅次于石油和天然气系统以及农业。

In July, Berkeley, California, became the first U.S. city to pass a law banning gas systems in new buildings.

今年7月，加州伯克利市成为美国第一个立法禁止新建筑物内安装天然气系统的城市。

But an inert gas system is always required when crude oil washing is operated.

但在原油洗涤操作中总是需要惰性气体系统。

(5) One hour before inert gas system operation is required (for tanker)?

(5) 惰性气体系统需要运行前一小时（液货船）？

An inert gas system was required on existing product carriers from 1 May 1983 and by 1 May 1985 for ships of 40-70,000 dwt and down to 20,000 dwt which are fitted with high capacity washing machines.

从 1983 年 5 月 1 日起，到 1985 年 5 月 1 日，现有的载重吨为 40-70,000 载重吨和低于 20,000 载重吨并配备大容量清洗机的船舶需要安装惰性气体系统。

In the case of crude oil carriers of 20-40,000 dwt there is provision for exemption by flag States where it is considered unreasonable or impracticable to fit an inert gas system and high-capacity fixed washing machines are not used.

对于 20-40,000 载重吨的原油运输船，如果船旗国认为安装惰性气体系统不合理或不切实际且不使用大容量固定式洗衣机，则有豁免规定。