The idiom "（ ）" is an example of the idioms adverbial in nature.
A、back and forth
B、make ends meet
C、call it a day
D、keep the pot boiling
【正确答案】：A
【题目解析】：本题考查常见的副词性习语。back and forth：来回地；make ends meet：量入为出；call it a day：停止；keep the pot boiling：维持生活。back and forth在句中相当于副词使用，而make ends meet，call it a day，keep the pot boiling在句中都相当于动词使用，属于动词性习语。故A选项符合题意。
