H\u00e0 N\u1ed9i: \u0110\u1eb7t ch\u1ec9 ti\u00eau chu\u1ea9n \u0111\u1ea7u ra ngo\u1ea1i ng\u1eef \u0111\u1ed1i v\u1edbi h\u1ecdc sinh l\u1edbp 12<\/a><\/blockquote><\/iframe>