Blue Sort 29

3. The study of the physical features of the earth.
4. Of, relating to, or produced by the internal heat of the earth.
5. The study of the origin of words.
6. Medical instrument for listening to the action of someone’s heart or breathing.
9. An instrument for measuring temperature.
13. An optical instrument designed to make distant objects appear nearer.
15. A branch of mathematics.
16. The scientific study of the behavior, structure, physiology, classification, and distribution of animals.
18. A small cavity in rock lined with crystals or other mineral matter.
19. An apparatus consisting of a tube attached to a set of mirrors by which an observer in a submarine can see things that are otherwise out of sight.
20. The continuous line forming the boundary of a closed geometric figure.
21. The science comprising the study of solid Earth.

1. Of or relating to heat.
2. An instrument used to measure speed.
7. The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.
8. A container that keeps a drink or other fluid hot or cold.
9. A device that automatically regulates temperature.
10. An optical instrument used for viewing very small objects.
11. An instrument measuring atmospheric pressure.
12. A diagram of the positions of the planets and signs of the zodiac at a particular time and place.
14. A collection of myths.
17. A straight line passing from side to side through the center of a circle.