常见例句雙語例句The most reactive coal is in the middling coal-bank;含灰量低的中等變質程度的煤氧化活性最高；The coals used included high-sulfur raw-coal, low-sulfur raw-coal and middling coal.所用煤種包括高硫原煤、低硫原煤、中煤。 返回 middling coal