PETRO
| Date | Clue |
|---|---|
| 2025-11-16 | Lead-in to dollar or chemical |
| 2015-05-16 | Rock: Prefix |
| 2013-06-09 | ___-Canada (northern gas station chain) |
| 2012-11-16 | Prefix with chemical |
| 2008-05-05 | Oil industry prefix |
| 2006-08-15 | Prefix with dollars |
| 2005-08-18 | Prefix with dollars |
| 2003-03-15 | Prefix with chemical |
| 1994-05-25 | Prefix with dollars |