Sandstorms are common (nature) disasters. They are often so thick that you cannot see the sun, and the wind is sometimes strong enough to move sand dunes. Sandstorms (main) occur in four places in the world, including Central Asia. Northwest China is part of the sandstorm center in Central Asia. Sandstorms in China appear (increase) in recent years as a result of "desertification". Sometimes Beijing is affected by sandstorms. They affect the traffic because the thick dust makes difficult to see.
some other disasters, sandstorms come with a warning. They can (forecast) some weeks before, but the (strong) of the storm sometimes surprises people. a sandstorm occurs, weather experts advise people not to go out. If you want to go out, you'd better wear (mask) because it's difficult to breathe and the dust makes people ill. To prevent sandstorms (come) nearer to Beijing, the government has made great efforts.
