Here's why:
* Skimming is a reading technique where you quickly scan a text to get a general idea of the content. It's useful for finding specific information. Tom isn't reading the entire book again; he's just looking for a specific section.
* Scanning is a similar strategy, but it's more focused on finding a particular word or phrase. Tom is likely skimming a larger portion of the book to find the character's introduction.
By skimming the relevant sections of the book, Tom is able to find the information he needs without having to read the entire story again.