A.上下針槽成90度相間交錯(cuò)配置 B.上下針槽成90度相對(duì)配置 C.上下針槽成180度相間交錯(cuò)配置 D.上下針槽成180度相對(duì)配置
A.1 B.2 C.4 D.6
A.1 B.2 C.3 D.4