💪🏼💪🏼 單字背了又忘？試試 VoiceTube 精心研發的線上課程吧！

undocumented

US /ˌʌn'dɑ:kjʊmentɪd/

・

UK /ˌʌn'dɒkjʊmentɪd/

B1 中級
定義影片字幕