George returned after the war,only_that his wife had left him. 选择A.to be told 这是什么语法知识

问题描述:

George returned after the war,only_that his wife had left him. 选择A.to be told 这是什么语法知识
麻烦详细通俗一点

【only + 不定式】在这里表示一个“意外” 且“不愉快” 的结果