Apostrophes and quotation marks can disappear from guest reviews after you import a CSV into the Review Importer.
Why this happens. The cause is the CSV encoding. When you save from Excel as plain CSV (Comma delimited), curly apostrophes and quotation marks are written in a legacy encoding that the Review Importer cannot read, so those characters are dropped.
What to do. Save the file as CSV UTF-8 (Comma delimited) instead, and the characters come through correctly.