You can't. But if you have a paragraph that is moving to the next page and
leaving a bunch of blank space at the bottom of the previous page, then
triple-click on the paragraph to select it, then click on Format | Paragraph
| Line and Page Breaks | uncheck the three boxes for "Page break before",
"Keep together", and "Keep with next" | OK. Or if you want to remove this
formatting from the whole document, press Ctrl+A to select all, then uncheck
the same three boxes.