closed book 详细解释

closed book

n. 不为人知的人或事, 无法解释的事物

英英释义

名词 closed book:

something that baffles understanding and cannot be explained

同义词:mystery, enigma, secret

补充

closed bookclosed bookn.1.一无所知的东西,已结束的事(计划、行动等)