| 1 | The oil will be refined. | |
| 2 | Their daily work is to refine crude oil. | |
| 3 | Philosophers and historians could help to refine the questions posed in political attitude surveys. | |
| 4 | We will continue to refine these processes to better study and understand the sophisticated nature of herbal medicines. | |
| 5 | It is interesting to see that Al Gore was constantly learning from each presentation and refining his message and his visuals along the way. |