用“shale rock”造句大全，shale rock造句

Then came a technological breakthrough in the United State, where firms found a way to free gas previously trapped in shale rocks.

Like America, Europe has vast beds of shale rock, in which innumerable bubbles of natural gas are trapped.

Soil in hilly regions in the middle of Sichuan Province is mainly a type of purple soil which has been developed from the purple shale rock.