have something down to a fine art idiom (UK also have something off to a fine art)
把…学到家；做…的技能达到炉火纯青的地步
to be able to do something very well or quickly, often because you have done it so many times
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。