（说话时）突然扯到题外， 突然背离原来的途径， 突然改变行径/思想
1. Go off at a tangent; go off on a tangent
这消息实在太突然了。
2. A noble place; inside as well as out, a noble place--a house in which you incontinently lost yourself if ever you were so rash as to go about it alone; a house in which no one room had any sympathy with another, every chamber running off at a tangent into an inner chamber, and through that down some narrow staircase leading to a door which, in its turn, led back into that very part of the house from which you thought yourself the furthest; a house that could never have been planned by any mortal architect, but must have been the handiwork of that good old builder--Time, who, adding a room one year, and knocking down a room another year, toppling down a chimney coeval with the Plantagenets, and setting up one in the style of the Tudors; shaking down a bit of Saxon wall there, and allowing a Norman arch to stand here; throwing in a row of high narrow windows in the reign of Queen Anne, and joining on a dining-room after the fashion of the time of Hanoverian George I.
一个高贵的地方，里里外外，全然是个高贵的地方——好一个府邸，如果你竟鲁莽得独自东闯西跑，你立刻就会茫然迷失；好一个府邸，其中没有一个房间同另一个房间有什么和谐一致之处，每个房间都逸出常轨，突入一个内室，再经由内室下到某一个楼梯上，楼梯通向一个门，门又导引你回到了老地方，你还自以为这是府邸中离此最远的部分哩；好一个府邸，任何人间的建筑师都设计不出来的，必定是善良古老的建设者——时间——亲手营造的。时间在这一年增加了一个房间，在另一年又弄塌了一个房间；一会儿推倒一个与金雀花王朝同时代的烟囱，另外垒起一个都锋王朝风格的烟囱；那儿推倒一点儿撒克逊时代的墙垣，这儿又容许建立一道诺曼拱门；既把安女王统治时期流行的一排又高又狭的窗子硬装了上去，又按照乔治一世时代的时髦样式修建了餐室，同一个自从威廉征服英国以来兀立至今的斋堂相毗连。
3. A noble place inside as well as out, a noble place--a house in which you incontinently lost yourself if ever you were so rash as to go about it alone a house in which no one room had any sympathy with another, every chamber running off at a tangent into an inner chamber, and through that down some narrow staircase leading to a door which, in its turn, led back into that very part of the house from which you thought yourself the furthest a house that could never have been planned by any mortal architect, but must have been the handiwork of that good old builder--Time, who, adding a room one year, and knocking down a room another year, toppling down a chimney coeval with the Plantagenets, and setting up one in the style of the Tudors shaking down a bit of Saxon wall there, and allowing a Norman arch to stand here throwing in a row of high narrow windows in the reign of Queen Anne, and joining on a dining-room after the fashion of the time of Hanoverian George I.
一个高贵的地方，里里外外，全然是个高贵的地方--好一个府邸，如果你竟鲁莽得独自东闯西跑，你立刻就会茫然迷失；好一个府邸，其中没有一个房间同另一个房间有什么和谐一致之处，每个房间都逸出常轨，突入一个内室，再经由内室下到某一个楼梯上，楼梯通向一个门，门又导引你回到了老地方，你还自以为这是府邸中离此最远的部分哩；好一个府邸，任何人间的建筑师都设计不出来的，必定是善良古老的建设者--时间--亲手营造的。
4. It's not easy to follow her think because she's always go off at a tangent.
老师在给我们讲述诗人生平故事的时候，突然把话题一转，讲开他自己的战争经历来了。
5. A lawyer should be skilled in the art of reasoning; it will not do in arguing a case to go off at a tangent into outside matters
律师要善于讲道理，辩论案件时突然离开本题说些不相干的话是不行的。