Assess students' understanding of the global carbon cycle by identifying major reservoirs (atmosphere, terrestrial biosphere, soils, oceans, lithosphere), comparing their relative sizes and typical residence times, describing key fluxes and processes (photosynthesis, respiration, decomposition, ocean uptake, sedimentation, fossil fuel combustion), performing simple flux/residence-time calculations and mass-balance reasoning, and evaluating human impacts (land-use change, fossil fuel emissions, mitigation and carbon management strategies). Include conceptual questions, short quantitative problems, and interpretation of carbon-budget graphs or tables.