A:is it that; ranged from
B:are there what; ranging from
C:is it that; ranging from
D:are there what; ranged from
如图,边长为4的等边三角形ABC中,E是对称轴AD上的一个动点,连接EC,将线段EC绕点C逆时针旋转60°得到FC,连接DF,则在点E运动过程中,DF的最小值是____ .
— How ________ money do we need?
— Thirty dollars.