When bamboo slips come apart, how can their backs help?
竹简散开以后，背面能帮什么忙？
如果一本书不是一张张纸，而是一支支用绳连起来的竹简，绳断以后该怎样排序？
If a book consists of bamboo slips tied together rather than paper pages, how can its order be recovered when the cords break?
当然可以研究文字，不过清华大学收藏的《系年》竹简，还在背面留下了线索。
The text can be studied, of course, but the Xinian bamboo manuscript at Tsinghua University also carries clues on the backs of its slips.
其中一类线索，是斜着经过多支竹简的刻痕。
One kind of clue is a slanting incision that continues across several slips.
单看一支，线只是一小段；把相邻的竹简放回一起，几段线就能接起来。
On one slip, the line is only a short segment; placing neighboring slips together allows the segments to connect.
研究者据此辨认竹材原本相邻的关系，帮助恢复紧密相接的排列。
Researchers use this to identify originally adjacent pieces of bamboo and help restore their close-fitting arrangement.
这里读的不是一句古文，而是材料自己留下的连接关系。
What is being read here is not an ancient sentence, but a relationship preserved in the material itself.
《系年》的背面还有次序编号，它们能更直接地帮助整理散乱的竹简。
The backs of the Xinian slips also have sequence numbers, which help more directly with arranging scattered slips.
然而，编号也不是绝对不会错：研究者发现了重复写号和漏号的现象。
Yet numbering is not infallible: researchers found repeated and omitted numbers.
刻痕和编号提供不同的帮助，也都需要结合实物细节来理解。
Incisions and numbers offer different kinds of help, and both require attention to the object’s details.
一本古书的背面，可能保存着它怎样成为一本书的答案。
The back of an ancient book may preserve answers about how it became a book at all.
