載入中... 相關課程 Back 1-4例題03百萬分濃度ppm 登入觀看 ⇐ Use this menu to view and help create subtitles for this video in many different languages. You'll probably want to hide YouTube's captions if using these subtitles. 1-4例題03百萬分濃度ppm 上傳學習單 下載學習單