The Boya Chinese Elementary 2 workbook uses QR codes that link to Peking University Press servers. However, these links frequently change or expire. When you hover over the QR code, nothing happens, or you get a 404 error.
You can find digital versions of the workbook and its answer keys on several academic and document-sharing platforms: Academic Portals : A direct PDF of the workbook exercises is often hosted on University Portals Digital Libraries hosts multiple uploads of the second edition workbook. boya chinese elementary 2 workbook pdf fix