Word formation and Writing: Difficult spellings

123456789101112131415161718
Across
  1. 7. STRENGTH
  2. 9. OCCASIONALLY
  3. 10. WIDTH
  4. 12. GOVERNMENT
  5. 14. SUCCESSFUL
  6. 16. INSTALLATIONS
  7. 17. DISAPPOINT
  8. 18. ENVIRONMENT
Down
  1. 1. CENTRE
  2. 2. NECESSARY
  3. 3. PROGRAMME
  4. 4. SCIENTIST
  5. 5. BEGINNING
  6. 6. POLITICIAN
  7. 8. ACCOMMODATION
  8. 11. IMMEDIATELY
  9. 13. RECOMMEND
  10. 15. DISAPPEAR
  11. 17. DEFINITELY