\u0110\u1ea1i s\u1ed1 – Ch\u01b0\u01a1ng 1 – B\u00e0i 4: \u0110\u1ed3 th\u1ecb c\u1ee7a h\u00e0m s\u1ed1 v\u00e0 ph\u00e9p t\u1ecbnh ti\u1ebfn h\u1ec7 t\u1ecda \u0111\u1ed9<\/a><\/blockquote><\/iframe>