| 例句 |
closed booknoun something hard to understand or explainthe couple's unorthodox marriage is definitely a closed book to those outside of the relationship conundrum, enigma, head-scratcher, mystery, mystification, puzzle, puzzlement, riddle, secret, why brainteaser, case, challenge, knot, matter, perplexity, poser, problem, stumper, trouble in 1913 |