短語(yǔ)詞組短語(yǔ)bobbin thread lower thread 縫紉底線(xiàn)bobbin thread knife 底線(xiàn)剪刀bobbin thread pull off 底線(xiàn)拉出量Bobbin thread slipping out 底線(xiàn)滑脫Adjusting the bobbin thread tension 底線(xiàn)張力的調(diào)節(jié) 返回 bobbin thread