A.定向鉆進(jìn) B.轉(zhuǎn)盤鉆進(jìn) C.導(dǎo)向鉆進(jìn)或轉(zhuǎn)盤鉆進(jìn)
A.0°到30° B.30°到60° C.60°到90°
A.20m B.30m C.40m