First of all, this is a top view of the south pole center. Because the shaded part represents the sixth day, one of oq and op is the 0-hour meridian and the other is the 180 degree meridian. Because mon is the terminator line, m and n are 6 o'clock and 18 o'clock (6 pm). So only the meridian when op is 0, that is, P is 0/24 point. Because oq does not meet the conditions of becoming zero. The distance from 24: 00 to 6: 00 and 18 are equal.

That is, on the diagram, you let the extension line of op pass through the equator and the H point. Hop is a straight line. Mon is the terminator line, and op and oh are o/24 and 12. Because hop divides fans equally, mon.

The answer is D.

At this time, the Antarctic is in the middle of the night, the earth is far from the sun, and the revolution speed is slow-A is wrong; Zhengzhou is in the northern hemisphere, so the days are long and the nights are short-B is wrong; When point P is 0, the difference between point P and point Q is 120 degrees, that is, 8 hours, and point Q should be 16 (4 pm)-C error;