unchallenged

a. 不成问题的,未引起争论的,未受到挑战的

unbowed, unbreakable, unbridled, unbroken, unbuckle, unburden, unbusinesslike, unbutton, unbuttoned, uncalled-for, uncannily, uncanny, uncared-for, unceasing, unceasingly, unceremonious, unceremoniously, uncertain, uncertainly, uncertainty, unchangeable, unchanging, uncharacteristic, uncharitable, uncharitably, uncharted, unchecked, unchristian, uncivil, uncle, Uncle Sam, Uncle Tom, unclean, uncleanness, unclear, uncoil, uncoloured (US uncolored), uncomfortable, uncomfortably, uncommitted,