Final answer:
The author is using foreshadowing techniques to build suspense and hint at a future event or revelation in the story.
Step-by-step explanation:
The author is using foreshadowing by having Jack go over the list for the 13th time, emphasizing the importance of not forgetting anything. This repetition and the focus on the number 13 create tension and suggest that something significant may happen related to the items in the box. Jack's behavior of talking to himself and arranging the items on the floor also adds to the sense of unease and anticipation. Overall, the author is using foreshadowing techniques to build suspense and hint at a future event or revelation.
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