长难句
长难句，顾名思义，就是又长又难的句子，主要是一些句中套句的复杂结构，其中包含了同位语、插入语、定语、不定式、分词、各种从句等，使得句子长达好几行。因此这些复杂的句型也往往成为了试题命制的重点所在，主要考查考生对句中的指代关系和句子层次的理解，常见的题型是推理判断题。考生应该加强训练自己对付长难句的能力，平时练习中有意识地去分解这些句子，理解其中的指代关系和句子层次。
【真题回放2007-Text4】
① Several massive leakages of customer and employee data this year – from organizations as diverse as Time Warner, the American defense contractor Science Applications International Corp and even the University of California, Berkeley – have left managers hurriedly peering into their intricate IT systems and business processes in search of potential vulnerabilities.
37. According to Paragraph 2, some organizations check their systems to find out
[A] whether there is any weak point.
[B] what sort of data has been stolen.
[C] who is responsible for the leakage.
[D] how the potential spies can be located.