The idiom "（）" is an idiom nominal in nature.

The idiom "（）" is an idiom nominal in nature.
A、white elephant
B、up in the air
C、​make it
D、tooth and nail
【正确答案】：A
【题目解析】：名词性习语有一个名词充当关键词，而且例句中用作名词， 如：white elephant（白象；无用而又累赘但又巨大、昂贵的东西）。up in the air是形容词性习语，make it是动词性习语，tooth and nail是副词性习语。答案为A。