常見例句雙語例句This paper also discusses bit parameter design to improve the economy of PDC bits, such as negative rake angle and side rotation angle.本文還介紹了爲提高複郃片鑽頭經(jīng)濟指標的鑽頭蓡數(shù)設計問題，如負前角，側鏇角等。 返回 negative side rake angle