indefatigability detail不易疲劳
relative indefatigability相对不疲劳性;相对不易疲劳性
fortitude indefatigability perseverance persevere不屈不挠
fortitude indefatigability pe不屈不挠
fortitude indefatigability perseerance perseere tenacity不屈不挠
fortitude indefatigability perseverance persevere tenacity不屈不挠