短语词组短语cable shares sag 索股垂度cable e sag 绳擞度cable sag detail 绳擞度cable with small sag 小垂度索cable sag effect 垂度效应flexible cable with large sag 大垂度柔索small -sag cable 小垂度索small sag cable 小垂度索sag of cable 垂度 返回 cable sag