| 例句 |
conundrumnoun something hard to understand or explainthe conundrum of how an ancient people were able to build such massive structures without the benefit of today's knowledge and technology closed book, enigma, head-scratcher, mystery, mystification, puzzle, puzzlement, riddle, secret, why brainteaser, case, challenge, knot, matter, perplexity, poser, problem, stumper, trouble in 1645 |