H\u00ecnh h\u1ecdc – Ch\u01b0\u01a1ng 1 – B\u00e0i 3: Ph\u00e9p vi t\u1ef1 v\u00e0 s\u1ef1 \u0111\u1ed3ng d\u1ea1ng c\u1ee7a c\u00e1c kh\u1ed1i \u0111a di\u1ec7n. C\u00e1c kh\u1ed1i \u0111a di\u1ec7n \u0111\u1ec1u<\/a><\/blockquote><\/iframe>