{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"Why do transactions expire in a blockchain?","a":"Consensus Mechanism: Consensus mechanisms in blockchain networks (such as proof of work, proof of stake, etc.) are used to  ensure the security and consistency of the network. The consensus mechanism judges the validity of transactions and decides whether to include them in the new block. Once a transaction is included in a block, it becomes a part of the blockchain and cannot be easily modified or deleted. Therefore, if a transaction fails to obtain consensus within a certain period, it will expire and"}]}],"pr":"a7bbaf25740045900d31318aa17fb295b46e6b47d7aa556733ccb182006938ff"}