21.   Now scientists are ready to link that explanation to the way dust clouds are polarized in the same direction.

22.   Now, scientists are ready to link that explanation to the way dust clouds are polarized in the same direction.

23.   Other offenders are the burning of oil and high-sulfur coal by industry, wood fires and even dust clouds from farms.

24.   On Thursday, neighborhood residents recalled the thick dust clouds and expressed concern about the impact on their health.

25.   Pancaking heavily to the floor, the skywalks spewed a gust of wind and huge dust cloud.

26.   Skies in New England could turn whitish at sunrise and sunset as the dust cloud makes its way out over the Atlantic.

27.   Stars take shape within huge dust clouds when interstellar gases contract under their own gravity, eventually condensing into hot clumps that ignite the hydrogen fusion process.

28.   Suddenly a column of tanks appeared, a dust cloud in its wake, dark specks nearly swallowed up in the enormous sea of sand.

29.   The blast came promptly at the appointed hour, and a giant mushroom dust cloud rose over what had been Yamit.

30.   The decline has some people forecasting an ominous dust cloud gathering on the horizon as we approach the millennium.