載入中... 相關課程 Back Optimal angle for a projectile part 2 - Hangtime 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. Optimal angle for a projectile part 2 - Hangtime 上傳學習單 下載學習單