Assess students' ability to recall the major greenhouse gases (carbon dioxide, methane, nitrous oxide, water vapor, ozone, and fluorinated gases) and identify their primary natural and human-made sources; suitable for short-answer or matching items focused on naming each gas and listing key natural (e.g., respiration, wetlands, oceans, soil processes) and human sources (e.g., fossil fuel combustion, agriculture, industrial emissions, refrigerants).