美国的页岩气革命在水力压裂法的推动下已经使天然气价格降到20世纪70年代石油危机天然气取得主导地位后的最低水平。
In the United States, the shale-gas revolution, facilitated by the development of hydraulic fracturing (“fracking”), has brought prices to their lowest levels since natural gas gained prominence after the oil crises of the 1970s.