They promised to keep touch with each other.
问题描述:
They promised to keep touch with each other.
答
keep in touch是固定搭配,表示“保持联络、联系”
each other意为“彼此;相互”
在翻译中,从简洁及语言习惯的角度出发,“彼此”可省略,译为:他们承诺要保持联系。
答
keep后面少了个“in”,他们互相承诺要报持联系