{"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":"Account Balance Backup: Backup the balances of all accounts to prevent asset loss during the upgrade process."}]}],"pr":"7189e4217fb4689b6548022c5c9faeb72c531b237f651d83f0d677681dff8036"}