The weather that often occurs when a warm front crosses the border is () A. Continuous precipitation B. The temperature drops and the air pressure rises C. The weather turns from cloudy to sunny D. Th

The weather that often occurs when a warm front crosses the border is () A. Continuous precipitation B. The temperature drops and the air pressure rises C. The weather turns from cloudy to sunny D. The temperature rises. A, because the warm air mass climbs slowly along the cold air mass, continuous precipitation often occurs when the warm front crosses the border, so it is correct;

B, the cold front is controlled by a single cold air mass after crossing the border, and the temperature drops and the air pressure rises, which does not meet the meaning of the question;

C, the weather from cloudy to sunny is the weather condition after crossing ahead, which does not meet the meaning of the question;

D, the warm front is controlled by a single heating mass after crossing the border, and the temperature rises and the air pressure drops, which does not meet the meaning of the question.

So choose: a