相关单词同义词difficult problem, puzzler, 近义词 problem 问题, riddle 谜, mystery 谜，神秘, enigma 难以理解的事物..., puzzle 难题, challenge 挑战, unknown 未知的, knot 结, brain-teaser 难题临近词convection, controversy, Conundrums, Conundrum of Figure相似词controverted election, contumacious, contumely, contusion, conurbation, convalesce, convalescence, convalescent, 返回 conundrum