| 例句 |
head-scratchernoun something hard to understand or explainwhy he chose to sink all of his money into a failing business is a real head-scratcher closed book, conundrum, enigma, mystery, mystification, puzzle, puzzlement, riddle, secret, why brainteaser, case, challenge, knot, matter, perplexity, poser, problem, stumper, trouble in 1902 |