Pasted text narrower than page width

I am a new user to Scrivener for Windows. I typed a page on Scrivener and it displays the width of my screen . I cut and pasted a chapter from Word. The document only covers 40% of the page width.

How can automatically convert the cut and pasted documents to full-width?

Use: Ctrl + Shift + V

Not a good solution if the source has italics, bold, or underline mixed with regular text.

Fix formatting by selecting text and choosing Format > Apply default formatting.
Default formatting is determined in Options > Editing > Formatting.

No italics, bold, underlines. Just text.

Also refer to How do I fix or convert formatting in my project, in the knowledge base.