On April 25, 2004, sandstorms broke out again in the ancient capital of Beijing. This was the eighth sandstorm in the spring of that year. Meteorological experts said that the dust storm came so early this year

The early drought and lack of rain in North China, warm weather, and rising temperatures are the special weather and climate background for the formation of sandstorms; the development of convective cells in front of the ground cold front into clouds is conducive to the development and intensification of sandstorms on small and medium scales system; the terrain conditions that are conducive to increased wind speed, that is, the narrow tube effect, are one of the favorable conditions for the formation of sandstorms; therefore, the frequent sandstorms in Beijing are closely related to cold front activities.

So choose: A.