1. balance 2. cast about 3. chew, chew on (часто chew on, chew upon) 4. cogitate 5. consider 6. contemplate 7. debate 8. debate a matter in one's mind (что-либо) 9. deliberate 10. hatch (идею, план и т. п.) 11. meditate 12. mull over 13. perpend 14. poise 15. ponder, ponder on, ponder over 16. revolve, revolve in the mind 17. study 18. think 19. turn (вопрос, проблему) 20. turn over 21. weigh