以下是gre閱讀長難句例項分析。gre長難句一直都是考生比較頭疼的一個問題，不是因為gre考試專門考察這部分，而是在gre閱讀中需要明白這些長難句才能理解整篇文章的意思。
1. Historians such as Le Roy Ladurie have used the documents to extract case histories， which have illuminated the attitudes of different social groups and have revealed how the authorities administered justice. 一類的'史學家利用這些文獻史料從中挖掘出某些個案史來，闡明瞭不同社會群體的態度，並揭示出當局是如何執行審判的。
解釋：逗號以後的內容都是修飾逗號以前的case history的。在which引導的非限定性定語從句中有一個插入語，我們可以看到這個插入語中又套了一個插入語but not confined to。
意群訓練：Historians such as Le Roy Ladurie have used the documents to extract case histories， which have illuminated the attitudes of different social groups and have revealed how the authorities administered justice.
2. It can be inferred from the passage that a historian who wished to compare crime rates per thousand in a European city in one decade of the fifteenth century with crime rates in another decade of that century would probably be most aided by better information about which of the following?
難句型別：複雜修飾
