A.抗拉系數(shù)B.保證系數(shù)C.應(yīng)力系數(shù)D.安全系數(shù)
A.1B.1.1C.1.2D.1.3
A.進(jìn)度要素B.安全要素C.設(shè)備要素D.生產(chǎn)要素