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Heating curves are common on the GED Science test. During a phase change (e.g., melting ice at 0°C), the added energy goes into overcoming intermolecular forces rather than increasing average kinetic energy of particles. Since temperature measures average kinetic energy, it remains constant until the phase change completes. Thus A is correct. B is an unfounded assumption; the plateau is expected, not an error. C is incorrect—heat continues to be absorbed; it is simply converted to potential energy (changing structure) instead of raising temperature. D would require evidence of perfectly balanced heat loss and gain, which is unlikely and not indicated. Interpreting graphs involves linking segments to physical processes: rising slopes (sensible heating) increase temperature; flat segments (latent heating) change phase. Key vocabulary: “latent heat,” “intermolecular forces,” and “kinetic vs. potential energy.” When analyzing such items, identify the state (solid/liquid/gas), the plateau temperature (e.g., 0°C for water melting at standard pressure), and remember that constant temperature during a phase change is a hallmark of energy being used to change state, not to speed particle motion.