challenge
名词复数：challenges
过去式：challenged
过去分词：challenged
现在进行时：challenging
词形变化：
形容词: challengeable | 动词过去式: challenged | 动词过去分词: challenged | 动词现在分词: challenging | 动词第三人称单数: challenges |
词义辨析：
同义:
vt.挑战; 怀疑; 反对
confront
question
defy
dispute
doubt
dare
同义参见:
invitation
controvert
suspect1
gage1
protest1
play
objection
mistrust