| 1 | These comprise asphalt, tar and waxes. | |
| 2 | But voters can see tar balls; erosion is tougher to spot. | |
| 3 | Canada is making desperate moves to prop up its tar sands and logging industries. | |
| 4 | Another source of concern: the discovery of 20 tar balls off Key West, Florida on Monday. | |
| 5 | Doctors also warn us of nicotine, tar, and many other toxic substances contained in cigarettes. |