In the geography of senior one, the latitude of the direct point of the sun at this time is the solar term of this day.

In the graph of 1, the latitude of the direct point of the sun at this time is (0), and the solar terms of this day are (vernal equinox) or (autumnal equinox).

2 Beijing time at the moment is (8); At noon on this day, the height of the sun at point A is (90).

3. Point (a) in the figure has the largest rotational linear velocity at points A, B and C; Point (c) is the most obvious deflection of the horizontal motion of the object.

4 If the direct point of the sun moves northward at this time, after three months, the order of sunshine hours of A, B and C from long to short is (BAC); The order of the height of the sun at noon from small to large is (cab).

Please use the positive solution.