短语词组短语Drawbar Organ 爵士风琴;音栓风琴drawbar trailer 牵引挂车;挂车slackless drawbar 无间隙牵引杆drawbar test 牵引试验drawbar stay 牵引钩卡子retractable drawbar 伸缩式联结装置free drawbar 铰接牵引杆drawbar height 联结点高度;牵引点高度drawbar pun 牵引杆拉力 返回 drawbar