英语短语out of out of 有由于和缺乏的意思.到底怎么判断呢比方说We did this out of nec

out of 作缺乏的意思时,前面要由系动词引导,如 be动词,get,become之类,例句：we are out of coffee 咱咖啡喝光了
你这句 We did this out of necessary 里面,out of 直接修饰谓语 did ,所以该是“出于什么目的”,可译成：因为有必要,我们才这么做的
另外你给的例句里面 necessary 是形容词 ,out of 后面应该接名词,应是We did this out of necessity