Across
- 6. a science that deals with the relationships between groups of living things and their environments
- 7. an agreement that you make with a company to get a publication or service regularly and that you usually pay for in advance
- 10. a medicine that is used to kill harmful bacteria and to cure infections
- 11. a vehicle with two wheels, usually moved by pedals
- 13. offering or expressing a choice
- 17. the original copy of a play, book, piece of music, etc., before it has been printed
- 18. a branch of mathematics that deals with points, lines, angles, surfaces, and solids
Down
- 1. to interchange repeatedly and regularly with one another in time or place; rotate
- 2. the study of life
- 3. happening twice a year
- 4. the act, process, or result of changing or altering something
- 5. the sacred writings of a religion
- 8. a substance that is added to the water in a vehicle's engine to prevent it from freezing
- 9. the use of science in industry, engineering, etc., to invent useful things or to solve problems
- 12. a large muscle at the front of the upper arm
- 14. a science that studies rocks, layers of soil, etc., in order to learn about the history of the Earth and its life
- 15. a substance that stops the harmful effects of a poison
- 16. the study of myths of a particular group or culture