單項(xiàng)選擇題中厚煤層(井工開(kāi)采)的劃分標(biāo)準(zhǔn)及其采區(qū)回采率規(guī)定為:()

A.煤層厚度:1.3~3.0m,采區(qū)回采率:≥80﹪
B.煤層厚度:1.3~3.5m,采區(qū)回采率:≥80﹪
C.煤層厚度:1.3~3.5m,采區(qū)回采率:≥85﹪


您可能感興趣的試卷

你可能感興趣的試題

1.單項(xiàng)選擇題文明生產(chǎn)對(duì)巷道積水超標(biāo)的規(guī)定為()

A.長(zhǎng)6m,深0.2m
B.長(zhǎng)5m,深0.2m
C.長(zhǎng)4m,深0.2m