11. Now the family networks are a primary driving force. 12. The primary driving force of Productivity growth is the key economic indicator of innovation ." 13. Safety will be the primary driving factor here. 14. Another possible primary driving force, but likely to be understated by modern historiography, was religious faith. 15. Ion propulsion has been tested in space before, but it had never been a spacecraft's primary drive . 16. But if you purchase a brand-new drive, you may want to use it as your primary drive . 17. We had really been expecting the U . S . to be the primary drive of these procedures. 18. Primary drive power comes from the gasoline engine, with the electric motor used to boost performance as necessary.19. Therefore, it is unlikely that individual identification was a primary driving force for the evolution of vocal learning. 20. Primary drive , taillight housing and timing covers were chrome-plated and the wheel rim centres were painted and lined.
