Final answer:
Sentence 4 foreshadows that Doodle is no longer present in the narrator's life.
Step-by-step explanation:
The sentence from the excerpt that is foreshadowing is Sentence 4 because it mentions that the grindstone begins to turn and time with all its changes is ground away, indicating that the narrator is remembering something or someone. The mention of Doodle in this sentence foreshadows that Doodle is no longer present in the narrator's life.
Learn more about foreshadowing in literature