{
    "hints":  [
                  {
                      "text":  "Fold the figure along Line ST in your mind.",
                      "level":  1
                  },
                  {
                      "text":  "Check if both sides of Line ST look exactly the same.",
                      "level":  2
                  },
                  {
                      "text":  "The two sides are different, so Line ST is not a line of symmetry.",
                      "level":  3
                  }
              ]
}