= 1+3

=4,

So the answer is 4;

(2)① Let the coordinates of point C be (x, x+2),

d(C，D)= | x- 1 |+| x+2-0 | = | x- 1 |+| x+2 |，

When x > 1, d(C, d) = x-1+x+2 = 2x+1> 3,

When -2≤x≤ 1, d(C, D)= 1-x+x+2=3,

When x 3,

So the minimum value of the right-angle distance between point C and point D is 3;

② The minimum right-angle distance between point C and point E is 2-2.