not hurt a fly. 说人心善，连只苍蝇也不会伤害。I don't think John would ever do something like that. He won't even hurt a fly. 我不相信John能干出这种事来，他连只苍蝇也不会伤害。She is the nicest person I've ever known. She won't hurt a fly. 她是我认识的最善良的人，连苍蝇也不会伤害