Adobe Acrobat Reader, now called Adobe Reader, offers several options for viewing PDF documents. The single-page view shows one page on the screen, with no other pages visible. The single-page continuous view shows one page after another, in a single column. The two types of split-screen view are called "two-up". The standard two-up view shows a spread of two pages on the screen, with no other pages visible. The two-up continuous view shows the side-by-side pages in a column.
Click the "View" menu In Adobe Reader.
Highlight "Page Display" and select "Two-Up" or "Two-Up Continuous". The document changes to a split-screen view.
Return to the "View" menu, highlight "Page Display" and select "Show gaps between pages" if you want a visible break between the pages of the PDF.