安常习故

Explanation: A: be content, are used; often: General; learning: habits; it: old friends. Conventions used to 　　Usage: Joint type; as predicate; that rigid and does not seek to change 　　Source: Qing Wei, "Mo Gu seven articles under the rule": "An ordinary practice so he and his ilk, who are safe now know who Chen cases, the provision of suspects who may refrain from shock and suspected, simultaneous and interference by cell Down? " 　　Examples: He ~ and his ilk. ★ Qing Wei Yuan "rule chapter seven" Thesaurus:  Always keep it safe