例1.读太阳直射点在地表的年运动轨迹图(见图1、图2),推测秋分日(9月23日)太阳直射点的位置是()A.a B.b C.c D.d这是一道被广泛应用的经典试题,解答此题目的关键是对图中箭头的理解。两图都以极地投影的方式表示太阳直射点在地表的年运动状况。图1中,地球自转方向是顺时针,为南极投影图,从b至a太阳直射点由赤道向南回归线移动,即b为秋分、a为冬至;图2为北极 Example 1. Reading the annual motion trace of the sun’s direct point on the Earth’s surface (see Figure 1 and Figure 2), it is assumed that the position of the direct sun on the fall day (September 23) is () Aa Bb Cc Dd This is a widely used The classic questions, the key to answer this question is the understanding of the arrow in the figure. Both figures show the annual movement of the direct sun at the Earth’s surface in a polar projection. In Figure 1, the Earth’s rotation direction is clockwise, as the Antarctic projection map, from b to a direct sun from the equator to the South tropic move, that b is the autumn equinox, a is the winter solstice; Figure 2 North Pole