They work by learning the details of the particular markup and figuring out where the actual data is. For example, in the illustration below the scraper extracts URLs from the del.icio.us.
它们通过分析网页特定的标注方式找到实际数据，例如，下图给出了抓取器怎么抓取del . icio . us的页面的示意图。
Even imagining things contrary to our knowledge contributes to the growth of knowledge, for example in learning from our mistakes.
即使是与我们知识相悖的想象也能够增长我们的知识，例如我们可以从错误中学习。
English speakers learning Spanish, for example, can write or speak descriptions of a vacation and receive feedback on their grammar and choice of idioms from native Spanish speakers on the network.
例如，以英语为母语的人学习西班牙语可以用写或说的方式描述一个假期，然后在网上便可以从以西班牙语为母语的人那儿收到有关语法及熟语的选择方面的反馈信息。
Let me give you the example from the Learning Annex.
我给你学习的榜样，从附件。
For example, higher scores on the memory and learning tests might stem from the fact that subjects who used ginkgo paid better attention to the initial instructions.
举例来说，使用银杏的病人在记忆与学习测验得到高分，可能是因为他们能够更加注意测验前的说明所致。
External representation plays an important role in learning from worked-out example.
外部表征在样例学习中发生着非常重要的影响。
Learning from your mistakes is one example of using failure.
从你的错误中学习是一个例子使用失败。
Feedback is provided not from of a teaching process as in supervised learning, but as punishments and rewards in the environment. Example problems are systems and robot control.
反馈并不像监督学习那样来自于训练的过程，而是作为环境的惩罚或者是奖赏。
We value and learn from each other. Such mutual learning, based on mutual respect and humility, sets a great example for exchange among different civilizations.
我们相互欣赏、相互学习，以尊重和谦逊的态度，借鉴吸收彼此文化中的精华，为世界文明交流互鉴提供了生动范例。
You are a good example of learning, we should learn from you.
你真是我们学习的好榜样，我们要向你学习。
This article illustrates how some ancient Chinese scholars from poor families make themselves by earnest handwriting and proofreading. Their learning spirit sets a valuable example for people today.
本文从门寒身素家贫，抄书读书成才和精校精抄等方面，阐述了体现在古人抄书活动中的可贵的读书治学精神。
Take Grey's Anatomy (2005-) for example: In 2011, Madisyn Seyferth, a 10-year-old American girl, saved her mother's life after learning CPR from the show.
拿《实习医生格蕾》（2005-至今）举例：在2011年，10岁的美国小姑娘MadisynSeyferth通过看电视剧学到的心肺复苏术，挽救了母亲的生命。
The impact of such learning on behavior is very different from, for example, learning by rote memorization of data.
这种学习有助于调节判断能力和分析能力，它对行为的影响完全不同于死记硬背。
The impact of such learning on behavior is very different from, for example, learning by rote memorization of data.
这种学习有助于调节判断能力和分析能力，它对行为的影响完全不同于死记硬背。
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