{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"The backup operations before blockchain upgrading include the following contents:","a":"Data backup: Backup all critical information in the blockchain network, such as transaction data, account information, contract data, etc., to  prevent data loss or damage."}]}],"pr":"cadb7d50aa21e508176eb1b1e51fadc87036cd9de557a11dd6e7279ec80bb83d"}