B\u00e0i t\u1eadp tr\u1eafc nghi\u1ec7m H\u00ecnh h\u1ecdc 12 \u2013 Ch\u01b0\u01a1ng 2 – B\u00e0i 1: Kh\u00e1i ni\u1ec7m v\u1ec1 m\u1eb7t tr\u00f2n xoay<\/a><\/blockquote><\/iframe>