indispensability
n. 不可缺少
1. the quality possessed by something that you cannot possibly do without
This electric drill is a indispensability special equipment at rag trade.
该电锁是服装工业不可缺少的专用设备之一.
Body and mental state are two aspects of body indispensability, they are mutually to contact interaction.
身体与心理是人体不可缺少的两个方面, 他们是相互联系相互作用的.