be one/another of life's great mysteries idiom
令人不解的事，使人困惑的事
to be something that is very difficult to understand
It really is one of life's greatest mysteries why that awful restaurant is busy every night. 那家很糟糕的餐厅每天晚上生意都很好，真令人费解。
江苏热线英汉汉英双解词典包含207361条英汉翻译词条，涵盖了常用英语单词及词组短语的翻译及用法，是英语学习的必备工具。