The history of the transmission of ancient Roman texts prior to invention of the printing press is reconstructed from evidence both internal and external to the texts themselves. Internal evidence is used to reconstruct the relationship of the surviving manuscripts of a Roman text to one another, as represented in a modern stemma codicum: a diagram depicting the genealogical relationship of surviving manuscripts and those the stemma’s editor believes existed at one time. Stemma are scholar’s only road maps to textual connections based on internal evidence, but they may paint a distorted picture of reality because they diagram the relationships of only those manuscripts known or inferred today. If surviving copies are few, the stemma perforce brings into proximity manuscripts that were widely separated in time and place of origin. Conversely, the stemma can also bestow a semblance of separation on manuscripts written within a few months of one another or even in the same room.
As described in the passage, a stemma is most closely analogous to which of the following?
A. a department store inventory list that excludes some departments
B. a map from which a large section has been torn off
C. a chronology that includes only major historical events
D. a family tree in which some generations are not recorded
E. a government organizational chart from which some agencies are omitted
该题是一个类比题，首先要明确关键词stemma的文章中的特点，再找类比选项。文章中stemma出现好几处，关键是要读懂后文stemma 与二句stemma codicum的关系，后文stemma 实际是stemma codicum 的同义缩写。根据二句对于 stemma codicum的冒号解释，就不难看出D选项最符合啦!