Across
- 2. nuclear energy
- 4. it will talk/speak
- 6. to throw out
- 9. electric car
- 11. they should
- 14. its our responsibility
- 18. to destroy
- 19. it will improve
- 20. it's going to be
- 21. its our duty
Down
- 1. solar energy
- 2. we're obligated to
- 3. it's going to be
- 5. electrical appliance
- 7. future
- 8. it's necessary
- 10. to collect
- 12. it's going to be
- 13. he/she is going to use
- 15. it's up to us
- 16. to develop
- 17. to discover