| Answer | Crossword Clue |
|---|---|
| INERTS | Nitrogen and carbon dioxide |
| GREENHOUSEGASES | Carbon dioxide and methane |
| TRIATOMIC | Like water and carbon dioxide |
| GASSES | Radon and carbon dioxide, e.g. (Var.) |
| ALVEOLI | Where oxygen and carbon dioxide are exchanged |
| SMOG | Pollutant containing nitrogen dioxide |
