备而不用

Explanation: Ready for emergencies, immediate temporary need. 　　Usage: The main predicate; as the predicate attribute; warning people to be fully prepared 　　Source: Qing Wu Jian "confused world," IX: "Although YAM, to have time, let the soldiers make a rumor, a few rows on the opening gun, the man may die a lot." 　　Examples: In the harvest year, we have a number of disaster food reserves, ~, enhance our resilience. Thesaurus:  untimely needs, Shall from time to time