Across
- 1. a heavy metal that can be harmful to health
- 4. large guns used in warfare
- 6. people who are killed or injured in a war or accident
- 9. areas where battles take place
- 11. substances that can cause an explosion
- 12. the presence of harmful substances in the environment
Down
- 2. large and powerful political entities that rule over territories and often have colonies
- 3. agreements between countries to support and defend each other
- 5. a sudden, radical, or complete change
- 7. underwater vessels used for military purposes.
- 8. poisonous substances
- 10. long, narrow ditches used for protection during.