题目掘工作面因瓦斯治理不到位造成甲烷浓度达到3.0%以上且持续时长超过多少,判定为瓦斯超限作业重大事故隐患?A. 5minB. 10minC. 30minD. 60min掘工作面因瓦斯治理不到位造成甲烷浓度达到3.0%以上且持续时长超过多少,判定为瓦斯超限作业重大事故隐患?A. 5minB. 10minC. 30minD. 60min题目解答答案B. 10min