Fort Knox
noun humorous uk/ˌfɔːt ˈnɒks/ us/ˌfɔːrt ˈnɑːks/
be like Fort Knox 像诺克斯堡般固若金汤
If a building or an area is like Fort Knox, it is impossible to enter or leave it because it is so well protected.
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。