Currently,the DTH rigs use generally a percussion rotary penetration sys-tem to generate the rotaing torque that produces a shearing action for breaking rock.是什么意思_Currently,the DTH rigs use generally a percussion rotary penetration sys-tem to generate the rotaing torque that produces a shearing action for breaking rock.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句