Across
- 3. energy
- 6. polluting
- 8. campaigner
- 10. organic
- 11. windscreen
- 12. reverse
- 13. stone
- 17. geothermal
- 19. concrete
- 20. swerve
- 21. clutch
- 23. tyre
- 24. bumper
- 26. renewable
- 27. well
- 28. coal
- 30. bronze
- 31. safety
Down
- 1. tunnel
- 2. manufacturing
- 4. stainlesssteel
- 5. rubber
- 6. pedestrian
- 7. thick
- 9. iron
- 10. overtake
- 14. hitchhike
- 15. driverless
- 16. pressure
- 18. earthquake
- 22. drill
- 25. hammer
- 29. length