| 1 | The footprints of tourists and the corrosiveness of sand storms are unknown. | |
| 2 | Sandstorms are becoming increasingly severe in northern China because of land degradation. | |
| 3 | Without trust, you cannot identify anything; it's like a sandstorm. | |
| 4 | Salt pans and other dry water features are among the most common sources of dust in the world. | |
| 5 | He said: "I think the droughts [and dust storms] in Australia are a harbinger. |