The circumferential angles of the same arc (or equal arc) are equal. As shown in the figure, points A, B, C and D are all

Is a point on ⊙O, then there is ∠ c = ∠ d.

Xiao Ming also found that if point E is outside ⊙O and on the same side of AB line as point D,

Have ∠ d > ∠E。

Please refer to Xiao Ming's conclusion and answer the following questions:

(1) As shown in figure 1, in the plane rectangular coordinate system xOy, the coordinates of point A are (0,7) and the coordinates of point B are (0,3).

The coordinate of point C is (3,0).

① Make the circumscribed circle of △ABC in the drawing 1 (keep the necessary drawing traces and don't write);

(2) If there is a point D on the positive semi-axis of the shaft, and ∠ACB =∠ADB, the coordinate of the point D is;

(2) As shown in Figure 2, in the plane rectangular coordinate system xOy, the coordinates of point A are (0, m) and the coordinates of point B are (0, n).

Where m>n>0. Point P is the moving point on the positive semi-axis of the shaft. When ∠APB reaches the maximum, directly write the coordinates of point P at this time.