The parallel cut is a key technique for excavation of tunnel s by deep-hole blasting.The depth of a blast-hole affects the cut bl asting greatly.是什么意思_The parallel cut is a key technique for excavation of tunnel s by deep-hole blasting.The depth of a blast-hole affects the cut bl asting greatly.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句