Across
- 2. of or having a shape that reduces the drag from air moving past
- 4. relating to or consisting of fragments of rock erupted by a volcano
- 6. strengthening the heart and lungs by making them work hard for several
- 7. a reddish clay that is used for pottery and tiles
- 9. a rock containing a cavity lined with crystals or other mineral matter
- 10. using the natural heat produced inside the Earth
- 11. or more
Down
- 1. relating to or occurring on Earth
- 3. a bright display of fireworks
- 5. performed in the air
- 8. to put air or a gas into something, such as soil or a liquid