Pass your cursor over the text you want to highlight and then click on the Bookmark icon at the top of the page. A window containing a text box will appear, and you can choose to enter a note in the text box and then click OK. This will place the listing of the highlighted text and the note on the left side of the screen under Bookmarks. If you do not enter text and just click OK, the bookmark text is indicated without a note.
To select text across multiple pages, go to Fit mode, smooth scroll to get the text you wish to select visible on both pages, and then select it.
Note: Bookmarks and highlighting are not copied when items are transferred to another computer.