Printable Scientifically Speaking Crossword

4. Earth's zone of air, water and soil capable of supporting life
6. Perhaps the most well-known scientist of the 20th century known especially for his theories of relativity and wild hair
9. Branch of science that explains the motion of airplanes in flight
10. Hill or mountain with a vent in the center
12. Plantlike organisms that produce more oxygen than all plants put together
13. Organ that sends blood through our bodies
15. The Ring of ______ - a zone of frequent earthquakes and volcanic eruptions in the Pacific Ocean
17. Covers over 70% of the earth's surface
18. Any kind of contamination of the earth
19. Burning of fossil fuels has turned this natural Effect into a negative one