{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"What specific content can be queried in a blockchain historical information query?","a":"Block header information: Including the previous block header hash value,  timestamp, random number, difficulty target, etc., these information is used to ensure that blocks are connected in sequence and verify the correctness of blocks."}]}],"pr":"cc3214328be5d7ee1c0553d0f645f618e6e72854bde7a844d14fffe0a53586f3"}