{
  "rubric": "Help the train move forward by typing the right answer to score, then click on the balloon and drop it on the correct wagon.",
  "attempts": "2",
  "Questions": [
    ["Q1 _______ is naturally found in the stratosphere.", "Ozone"],
    [
      "Q2 _______ is the largest contributor to the greenhouse effect.",
      "Water vapour"
    ],
    [
      "Q3 ______ is the increase in the Earth's temperature due to increase of greenhouse gases.",
      "Global warming"
    ],
    [
      "Q4 A greenhouse is a __________ where we grow plants, especially during winter.",
      "glasshouse"
    ],
    ["Q5 Trees help to clean the ______ .", "air"]
  ]
}