{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"What backup measures need to be taken before upgrading blockchain?","a":"Transaction Data Backup: Backup  all unconfirmed transactions to ensure that these transactions can proceed normally after the upgrade."}]}],"pr":"0d162d08538f0d0fd8e383419d75fa3ab0e954360deb2c8a3786ee99a33ba794"}