I want to know the answer to the following question:
Which model explains why bob has an easier time reading a book, and then discussing it rather than reading two books?
All the background I'm provided with is that "The working memory model explains many practical observations, such as why it is easier to do two different tasks (one verbal and one visual) than two similar tasks (e.g., two visual), and the aforementioned word-length effect.". Is that enough to answer the question?