例句與造句

1. mine plans-petrography-part 5 : hard coal mining
   礦山平面圖.巖相學(xué).第5部分:煤礦
2. elastomere scraper plates for belt conveyors in hard coal mines
   無煙煤礦山的皮帶輸送機用彈性體刮板
3. explosibility of coal dust in underground hard coal mining-tests and assessments of coal dust-air-mixtures and hybrid mixtures
   地下煤礦煤塵易爆性.煤塵空氣混合氣體和混合物的試驗
4. It's difficult to find hard coal mining in a sentence. 用hard coal mining造句挺難的