It is difficult to the point of impossibility for the average reader under the age of forty to imagine a time when high-quality arts criticism could be found in most big-city newspapers.
【核心词汇】
high-quality a. 高质量的
criticism n.批评，批判
【结构分析】
it作形式主语，动词不定式短语to imagine a time when high-quality arts criticism could be found in most big-city newspapers在句中充当实际主语。其中的for average reader under the age of forty是动词不定式短语中imagine这一动作的真正施动者，to the point of 表示“达到……的程度”，to the point of impossibility表示“达到几乎不可能的程度”。另外，该短语中的when high-quality arts criticism could be found in most big-city newspapers是定语从句，用来修饰其前面表示时间概念的名词time。
【参考译文】
40岁以下的普通读者难以想象，甚至不可能想象出一个在许多大城市报纸上都能找到高质量艺术评论的时代。