如图所示,正方形ABCD的面积为12,△ABE是等边三角形,点E在正方形ABCD对角线AC上有一点P,使PD+PE的和最小,则这个最小值为( )
A:2
B:23
C:4
D:42
My father _____ bus to work and it takes a long time ____ for one.
下列有关生命活动调节的现象,合理的是( )