{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How does the block hash in blockchain ensure the immutability of data?","a":"Block structure: Each block in a blockchain consists of a block header and a block body. The block header contains the hash  value of the previous block, the hash value of the current block body, and a timestamp."}]}],"pr":"b1ec1c9f6e1a5b423c1870158ef9b70c302c116334ef164617f5449ccf4d53c8"}