{"p":"can-20","op":"mint","tick":"can","amt":"1000","rows":[{"df":"qa","content":[{"q":"How can blockchain be applied to electronic evidence preservation?","a":"Blockchain technology  provides a reliable technical basis for the supervision and implementation of laws and"}]}],"pr":"c15d0a39267aeee7a1515d857b8421e468e90937a6a0a9771c2312caa53aa8bc"}