单项选择题
A.1.10~1.80B.1.30~1.80C.1.50~1.80D.1.70~1.80
A.1.0~1.8B.1.2~1.8C.1.4~1.8D.1.6~1.8
A.挂件连接B.背拴连接C.背槽连接D.背卡连接