Changing the page layout is especially useful when you want to zoom out to get an overview of the document layout. You can use the following page layouts when viewing PDF documents:
Displays one page at a time, with no portion on other pages visible.
Displays pages in a continuous vertical column that is one page wide.
Displays each two-page spread with no portion of other pages visible.
Displays facing pages side by side in a continuous vertical column.
You can also display buttons for each of these options in the Display Pages toolbar by choosing Tools > Toolbars > More Tools, and selecting them in the More Tools dialog box.