Ключевые слова: ball, dependable, durable, endless, enduring, everlasting, firm, hardened, hardy, immune, impeccable, indestructible, inviolable, joint, lasting, permanent, persevering, persistent, prolonged, reliable, resilient, robust, rugged, secure, solid, stalwart, steady, strong, sturdy, substantial, sustainable, tenacious, tough, toughened, unyielding, vigorous,