必要
反义词
按词义分组列出，使用时请结合具体语境。
require as useful, just, or proper; "It takes nerve to do what she did"; "success usually requires hard work"; "This job asks a lot of patience and skill"; "This position demands a lot of personal sacrifice"; "This dinner calls for a spectacular dessert"; "This intervention does not postulate a patient's consent"
基本解释
不可缺少；非这样不行开展批评和自我批评是十分～的ㄧ为了集体的利益，～时可以牺牲个人的利益。