然而，随着矿井开采范围的延深，松软煤层的分布范围呈不断扩展趋势。

However, with the extension of mining depth, the distribution of soft coal seam has been expanding.

youdao

然而，随着矿井开采范围的延深，松软煤层的分布范围呈不断扩展趋势。

However, with the extension of mining depth, the distribution of soft coal seam has been expanding.

youdao