On the outskirts of the city , smokestacks belched carbon and sulfur into the putrid mist that enveloped them .
在城市的郊区，烟囱向周围的薄雾喷出碳和硫磺。
Following this first " warm and wet " period , the face of mars began to change drastically as volcanoes belched out sulfur , oxidized , and formed corrosive acid rain .
Air pollution was not the most immediate of problems but the canopy of smoke that belched from industrial and domestic chimneys began to attract attention .
虽然空气污染不是最紧迫的问题，但是不断从工厂和住家烟囱里喷出的弥天烟雾开始引起大家的关注。
The huge amounts of methane stored in the arctic permafrost are belched into the atmosphere , causing more warming .
