A.金剛石鉆頭鉆進(jìn) B.合金鉆頭鉆進(jìn) C.單動(dòng)雙管鉆具鉆進(jìn) D.鋼粒鉆進(jìn)
A.不大于50mm B.不大于150mm C.不大于100mm D.不大于200mm