qiānyǐn bōshù

== Mandarin == === Romanization === qiānyǐn bōshù (Zhuyin ㄑㄧㄢ ㄧㄣˇ ㄅㄛ ㄕㄨˋ) Hanyu Pinyin reading of 牽引波束 / 牵引波束