打牢基础是否能轻松应对考试呢?
不够，还需要在此基础上总结方法。比如中值定理相关的证明题是令不少考生头痛的一类题。考生把基础内容(闭区间上连续函数的性质、费马引理、罗尔定理、拉格朗日定理、柯西定理)掌握好后(定理内容能完整表述，定理本身会证)，直接做真题，很可能没什么思路，不知道朝哪个方向想。

The Higher the Heel, the Wealthier the City, New Research Says

新研究表明：鞋跟越高 你所在的城市就越有钱

Do you live in your high heels? Chances are you live in a wealthy city, new research suggests.

你每天都穿高跟鞋吗?一项新研究表明：如果是，那么你很有可能生活在一个富有的城市。

American women who relocate to wealthier cities are more likely to adopt the fashion preferences of those around them (including higher stilettos), while those who move to poorer cities are more likely to eschew the local norm and stick with their previous wardrobe style, a new study from Tepper School of Business reveals. Heel height increases in wealthier areas where the local style accepts the higher heel as standard, assert the school’s associate professor of marketing Jeff Galak and his co-authors in the paper, titled “Trickle-down preferences: Preferential conformity to high status peers in fashion choices”.

泰珀商学院的新研究表明，迁移到更富有的城市的美国女性更有可能受到周围人潮流偏向的影响(越来越高的细高跟鞋就包括在内)，而那些迁到相对来说贫穷的城市的女性，则更有可能避开当地的流行趋势，坚守她们之前的装扮风格。泰珀商学院的营销学的副教授杰夫·加拉克与其他人合著的论文，题为“滴流趋势：与富有群体保持一致的潮流选择”。该论文表明，在那些更富有的地区，将越来越高的鞋跟看作是一种潮流标准，因而在这些城市，女性鞋跟高度不断增加。

“Studying heel height may seem like an unusual way to understand social influence, but it’s actually a perfect setting,” said Galak. “Fashion choices are highly visible decisions that are influenced by social norms and pressures.”

“研究鞋跟的高度似乎是了解社会影响的一种不同寻常的方式，但实际上它是一种极佳的方法，”加拉克说。“从潮流的选择中，我们很明显就能看出社会规范和社会压力对其产生的影响。”

The researchers studied 16,236 shoe purchases by 2,007 women across more than 180 US cities over a five-year period. They found that women’s heel height changed along with their relocation, whenever they moved to a city whose median income was higher than earnings in their original hometown.

研究者们调查了美国180个城市2007名女性在五年中购买的16236双鞋子。他们发现，随着这些女性所在地点的改变，她们鞋跟的高度也随之变化，当她们搬到一个城市，如果这个城市的平均工资水平要高于原来所在的城镇，那么她们的鞋跟高度会发生变化。

Census figures reveal that more than 7 million Americans relocate across state lines annually, and Galak admits that heel height could be the tip of the iceberg when it comes to conformity and shopping habits. “There is, of course, still more work to be done to understand how people, in general, balance the complexity of maintaining their own sense of individuality while trying to be part of a larger group,” he says.

一致的数据表明，每年，有700多万美国人会迁到本国的另一个州。加拉克承认，谈到潮流和购物习惯时，鞋跟高度只是冰山一角。他说：“当人们在追随大众潮流时，他们是如何平衡个性维持的复杂性呢?要想从整体上了解这一问题，我们还有很多工作要做。”