◎ 间不容发 jiānbùróngfà(1) [a seamless heavenly robe——flawless;by the skin of one's teeth;by a hair's breadth;the difference is as narrow as a hair's breadth]∶中间放置不下一根头发,形容相距极微律厤迭相治,其间不容发。——《大戴礼记》(2) [the situation is extremely critical;within a hair of;within an inch of]∶比喻情势危急到极点其出不出,间不容发。——汉· 枚乘《上书谏吴王》-----------------国语辞典:距离十分相近,中间不能容纳一丝毫发。比喻情势危急。《文选.枚乘.上书谏吴王》:「系绝于天,不可复结,坠入深渊,难以复出,其出不出,间不容发。」《五代史平话.唐史.卷下》:「事机之来,急如弩箭,投机之会,间不容发。」近危如累卵
◎ 隔行如隔山 géháng rú géshān[difference in profession makes one feel worlds apart] 比喻不同职业、行业的专门知识、技艺相距甚远-----------------国语辞典:(谚语)非本行如同隔一座山一样的遥远。比喻不了解其中甘苦状况。如:「有道是隔行如隔山,别人怎能体会编辑辞典的苦处。」英语 different trades, worlds apart (idiom); to sb outside the profession, it is a closed book