This paper introduces research and development of DH pneumatic perforating machine, hydraulic percussion hammer and trajectory -controlled pneumatic perforating machine and their application.是什么意思_This paper introduces research and development of DH pneumatic perforating machine, hydraulic percussion hammer and trajectory -controlled pneumatic perforating machine and their application.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句