Across
- 1. The human heart __________ (beat) approximately 70 times per minute.
- 4. The human brain __________ (process) vast amounts of information every second.
- 7. Gravity __________ (attract) objects toward the center of the Earth.
- 8. The human body __________ (contain) billions of cells.
- 9. Ice __________ (float) on water because it is less dense.
- 10. Oxygen __________ (combine) with hydrogen to form water molecules.
Down
- 1. Water __________ (boil) at 100 degrees Celsius.
- 2. Sound __________ (travel) faster through solids than through gases.
- 3. The Earth __________ (rotate) on its axis once every 24 hours.
- 4. Plants __________ (photosynthesize) to produce oxygen and glucose.
- 5. The sun __________ (emit) light and heat energy.
- 6. The moon __________ (orbit) around the Earth approximately once every 27.3 days.