{"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":"Block Data Backup: Backup the entire blockchain's block data, including block headers and block bodies. These data can be obtained  through a blockchain browser or your own node."}]}],"pr":"62b68c3dcfdc613b03325adca4392f3c4fe2ccdc8f3640a0ca5708a87c1316cd"}