There is no time to tell whether it is the vernal equinox or the winter solstice on the geography test paper.

Such a map judges the solar terms according to the extreme day and night conditions in the polar regions. As long as one is judged, the others are inferred counterclockwise. For example, on the left side of the earth, there is an extreme day in the Arctic Circle, and it can be judged that this position is the summer solstice. The counterclockwise direction is the autumnal equinox, the winter solstice and the vernal equinox.