英语词汇“a closed book”的翻译、意思、用法、释义-英汉汉英词典

单词	a closed book
释义	a closed book 完全不懂的学科；尚未揭开的秘密，不为人所知的事，无法理解的事(或人)；高深莫测的事物；谜以上来源于：《21世纪大英汉词典》
随便看	level at the moon level,a water level axis level based system level best levelbest level board level bombing level bottom community level braking level bubble level capacity level chamber level chambered spirit level checker level checking level circuit level circuit error level circular level code level coding level compensator level compounded level compounded, flat compounded level-compound excitation