1. human respiratory system, oxygen transport in blood, vertebrate lungs, comparative anatomy
2. infectious diseases, pathogens (viruses, bacteria, others), hygiene practices, disease prevention
3. chemical reaction indicators, temperature/color change, accurate measurement, data interpretation
4. physical changes, boiling vs evaporation, phase reversibility, thermal conductivity of materials
5. force diagrams, applied/friction/gravity/normal forces, motion analysis, mass vs weight, Moon gravity
6. electrical circuits (symbols, parallel setup), soil composition (gravel, sand, clay, humus), Solar System model, puberty changes