var json2 =({
  "?xml": {
    "@version": "1.0",
    "@encoding": "UTF-8"
  },
  "text": {
    "heading1": {
      "@fieldnumber": "0",
      "#text": "目的"
    },
    "objective": {
      "@fieldnumber": "1",
      "#text": "了解如何找到一个几何体的对称面。"
    },
    "heading2": {
      "@fieldnumber": "2",
      "#text": "总结"
    },
    "summary": {
      "@fieldnumber": "3",
      "#cdata-section": "&#187;  一个对称面将一个几何体分割成两个部分，这两部分是互为镜像的、完全相同的形状。一个几何体可以有多个对称面。"
    }
  }
});
