A.80°;45° B.60°;45° C.80°;60° D.50°;45°
A.鋼絲繩安全系數(shù)應(yīng)大于5 B.鋼絲繩安全系數(shù)應(yīng)大于6 C.鋼絲繩安全系數(shù)應(yīng)大于7 D.鋼絲繩安全系數(shù)應(yīng)大于8
A.30° B.25° C.20° D.15°