A.90 B.80 C.70 D.100
A.900 B.1200 C.1500 D.1000
A.1倍鋼絲繩直徑深度時(shí) B.1.5倍鋼絲繩直徑深度時(shí) C.2倍鋼絲繩直徑深度時(shí) D.2.5倍鋼絲繩直徑深度時(shí)