已知等差数列{a_n}的前n项和为S_n=n²+pn+q（p，q∈R），且a₂，a₃，a₅成等比数列．

    When Abraham Lincoln was young, he worked in a store. One day a woman came into the store and bought some things. They added up to two dollars and six and a quarter cents.

    The bill was paid, and the woman was satisfied. But the young storekeeper, not feeling quite sure about his calculations(计算), added up the things again. To his surprise, he found that it should have been but two dollars.

    “I've made her pay six and a quarter cents more,” said young Abe, upset.

    It was an unimportant thing, and many salespersons would forget it, but Abe was too careful for that.

    The money must be paid back, he decided.

    At night, he closed the store and walked to the home of his customer. He explained the matter, paid over the six and a quarter cents, and returned satisfied.

    Here is another story of young Lincoln's strict honesty. A woman entered the store and asked for half a pound of tea. The young man weighed it out. This was the last sale of the day.

    The next morning, when beginning his duties, Abe discovered a four-ounce weight on the scales(磅砰). It flashed upon him at once that he had used this in the sale last night, and so, of course, given his customer short weight. Many people would not have been much worried by this discovery. But Abe weighed out four ounces of the tea, shut up the store, and carried it to the customer. I think that the name, so often given in late times to President Lincoln, of “Honest Old Abe", was well deserved(应得的).

   他一动不动地仰面躺着，现在，他能够听到病狼一呼一吸地喘着气，慢慢地向他逼近。①它愈来愈近，总是在向他逼近，好象经过了无穷的时间，但是他始终不动。②它已经到了他耳边。那条粗糙的干舌头正象砂纸一样地磨擦着他的两腮。他那两只手一下子伸了出来——或者，至少也是他凭着毅力要它们伸出来的。③他的指头弯得象鹰爪一样，可是抓了个空。敏捷和准确是需要力气的，他没有这种力气。

    那只狼的耐心真是可怕。这个人的耐心也一样可怕。 这一天，有一半时间他一直躺着不动，尽力和昏迷斗争，等着那个要把他吃掉．而他也希望能吃掉的东西。有时候，疲倦的浪潮涌上来，淹没了他，他会做起很长的梦；然而在整个过程中，不论醒着或是做梦，他都在等着那种喘息和那条粗糙的舌头来舐他。

    他并没有听到这种喘息，他只是从梦里慢慢苏醒过来，觉得有条舌头在顺着他的一只手舐去。他静静地等着。狼牙轻轻地扣在他手上了；扣紧了；狼正在尽最后一点力量把牙齿咬进它等了很久的东西里面。可是这个人也等了很久，那只给咬破了的手也抓住了狼的牙床。于是，慢慢地，就在狼无力地挣扎着，他的手无力地掐着的时候，他的另一只手已经慢慢摸过来，一下把狼抓祝五分钟之后，这个人已经把全身的重量都压在狼的身上。他的手的力量虽然还不足以把狼掐死，可是他的脸已经紧紧地压住了狼的咽喉，嘴里已经满是狼毛。半小时后，这个人感到一小股暖和的液体慢馒流进他的喉咙。这东西并不好吃，就象硬灌到他胃里的铅液，而且是纯粹凭着意志硬灌下去的。后来，这个人翻了一个身，仰面睡着了。