单项选择题
A.Q=nqp B.Q=mqp C.Q=nqc D.Q=npc
A.18 B.15 C.25 D.20
A.从轨面高1250mm至2600mm范围 B.从轨面至4800mm范围 C.从轨面高1250mm至4800mm范围 D.从轨面高1250mm至3600mm范围
A.50mm B.20mm C.100mm D.80mm
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