Ensure is impossible. You can do pretty good, but a lot depends on the way the PDF was created. If the PDF was created with the tagging markup, then you may get an extremely good output. If it is from a scan, you would be lucky to get anything close to the PDF view and may have font issues depending on the way the scan was done.
Try the export (or Save As Other>DOCX) and give some more specific questions that can be answered in a more direct sense.