{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"The development history of blockchain is as follows:","a":"Blockchain  2.0 era (2013 to present): With the birth of Ethereum, blockchain technology entered the era of smart contracts."}]}],"pr":"72e5cfa145e273d692c176ba79fe03a043bdec63e3c1c9246ae44042b33912d5"}