Which of the following is not a major problem to be solved in mine field development method?( ) A: Mining methods B: Shaft (adit) form C: Number of mining levels D: Layout of main haulage roadway

Which of the following are common forms of comprehensive development?( ) A: Development of main inclined shaft-auxiliary vertical shaft B: Development of main shaft-auxiliary inclined shaft C: Main shaft-auxiliary adit D: Multi-shaft areas development

What are the advantages of adit development? It is widely used in some mining areas with mountains and hills in China.( ) A: The system is simple and convenient for construction B: The system is complex, but the construction is convenient C: The construction is difficult, but the system is simple D: The construction is convenient and adaptable