A.45°~60° B.60°~75° C.75°~90° D.45°~75°
A.鎢鈷類 B.鎢鈦類 C.鎢鈦鈷類 D.鈦鉆類
A.0.01-0.02 B.0.01-0.04 C.0.02-0.04 D.0.01-0.04