1 | Trees can also reduce the strong odor of ammonia gas. | |
2 | They can also reduce the strong smell of ammonia gas . | |
3 | The trees capture dust, ammonia and odors in their leaves. | |
4 | Ammonia gas released by fertilized cropland is a cause of air pollution , the . | |
5 | Ammonia gas released by fertilized cropland is a cause of air pollution. |