small coal mines的用法和樣例：
例句
- Medium and small coal mines in north of Shaanxi Province generally adopt longwall remaining coal pillars support mining.
摘要長(cháng)壁留煤柱支撐法開(kāi)采是陜北中小煤礦普遍采用的一種采煤方法。 - The belated enforcement of mining safety standards has led to closure of many small mines and temporary shortage of coal.
采礦安全標準姍姍來(lái)遲后，許多小煤礦被關(guān)閉，導致了暫時(shí)性的缺煤。
