{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"What are the real problems faced by the development of blockchain?","a":"Security and privacy protection:  The blockchain technology itself has high security, but as time goes by, attack methods are constantly upgraded. How to ensure the security of the blockchain system and protect user privacy has become a real challenge."}]}],"pr":"8b96556fc2868ac374c0aeb01ddf7ad343a9c28344b19042e1b64d6cc31ed558"}