Each question gives instant feedback with an explanation, and the bar at the top tracks how far through you are. Flag any question to revisit it later in Key Revision. The quiz opens in a focused full-screen view, and questions are picked at random each time.
Figures reflect current published standards — BS 7967:2015 (combustion analysis; CO/CO₂ ratio action level 0.0040), analysers to BS EN 50379-3, and GIUSP / IGEM/G/11 for unsafe situations. The manufacturer's stated combustion figures take precedence where given. Confirm the editions your centre is testing to. Revision support, not a substitute for your ACS training.