Ch\u01b0\u01a1ng 1 – B\u00e0i 7: \u0110\u1ea5t n\u01b0\u1edbc c\u00f3 nhi\u1ec1u \u0111\u1ed3i n\u00fai (ti\u1ebfp theo)<\/a><\/blockquote><\/iframe>