The famous racehorse Secretariat had to be destroyed because of a painful, incurable hoof disease.6/30ThefamousracehorseSecretariathadtobedestroyedbecause of a painful, incurable hoof disease.disablingvexatiousdangerousirreparableGiải thíchĐáp án D incurable = irreparable: không thể cứu chữa được