When reading a standard text book, such as a general text in Nursing, information can be gathered by using a variety of strategies by noting the overall structure of the text book in terms of:

the subdivision of the book into chapters,
the subdivision of chapters into sections,
and the subdivision of sections into subsections.

It can also be extracted quickly at the level of subsections by noting the way topic sentences are used to:

introduce the main focus of a paragraph and
present an argument or an overall outline of ideas presented in the subsection.

To show you to gather information quickly at each of these different levels, we have modelled this process using a normal text.

Sample text