This can cause physical pain and produce gas in the stomach.

这会导致机体疼痛，并在胃中产生气体。

Producers have boosted supplies and recoverable reserves in the United States by combining horizontal drilling with hydraulic fracturing, also called fracking, to produce gas from shale formations.

天然气生产者已经通过水平钻孔技术和水力破碎技术的结合从页岩结构中开采天然气，从而来增加天然气供应和可恢复储备。