(0 7 4? The front line of Zhabei District refers to the intersection of the front line and the ground. The picture shows the distribution of fronts and rain areas in a certain area of China from May t

(0 7 4? The front line of Zhabei District refers to the intersection of the front line and the ground. The picture shows the distribution of fronts and rain areas in a certain area of China from May to July 3, 1977. A before the cold front crossed the border on February 22, a place was controlled by warm air flow, and the temperature was not the lowest, which did not meet the question.

B, 22, when the cold front crosses the border, the temperature drops and rainy weather appears, but the temperature is not the lowest, which does not meet the meaning of the question;

C, 23, after the cold front crosses the border, the temperature drops, but it is not the lowest time of the day, so it does not meet the question;

D. according to the movement of the center plane in the picture, it is judged that a is the situation after the front crossing on February 23. Generally, the ground loses the most heat around sunrise in a day, so it is the time when the temperature is the lowest. Therefore, from February 22 to February 23, the lowest temperature in A appeared around sunrise on February 23, so it is correct.

Therefore, choose: d.