A.節(jié)省接單根時(shí)間B.倒劃眼防止卡鉆C.下鉆劃眼D.節(jié)省定向井鉆進(jìn)時(shí)間
A.箱式B.掛式C.臺式D.立式
A.當(dāng)轉(zhuǎn)動力矩不平衡時(shí),主杠桿繞支點(diǎn)微擺B.當(dāng)轉(zhuǎn)動力矩平衡時(shí),主杠桿即穩(wěn)定不再擺動C.當(dāng)轉(zhuǎn)動力矩不平衡時(shí),主杠不再擺動D.當(dāng)轉(zhuǎn)動力矩平衡時(shí),主杠桿繞支點(diǎn)微擺