Final answer:
Elements of plot suitable for young readers include an episodic structure, fast action with strong conflict, and a chronological structure, while flashbacks are not typically appropriate due to their complexity.
Step-by-step explanation:
The crucial elements of plot that are appropriate for readers younger than 8 or 9 include an episodic structure, fast action and strong conflict, and a chronological structure. The element that is not typically appropriate for young readers is a flashback. Flashbacks can be complex and might confuse younger readers who are still learning to understand narrative structure and time sequence. On the contrary, a chronological plot follows a linear path that is easier for children to follow, while episodic structures can present stories in bite-sized, manageable segments. Fast action and strong conflict help to keep younger readers engaged with the straightforward momentum of the story.