{
  "air": {
    "plane": [
      "Boeing 737",
      "Boeing 747"
    ],
    "helicopter": [
      "Bell",
      "Eurocopter"
    ]
  },
  "ground": {
    "car": [
      "Porsche",
      "Lamborghini"
    ],
    "truck": [
      "Man",
      "Volvo"
    ]
  }
}