{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How to obtain the latest block hash in a blockchain to ensure the validity of transactions and expiration time?","a":"Connect to the blockchain network: First, you need to establish a  connection to the blockchain network, which can be achieved by using a blockchain client, API interface, or third-party services."}]}],"pr":"1afa4aa9dc9280a8befdd6c4bd5dc7bd2dd54edbd4c59b59a66a5fe685398e8d"}