圆的半径决定圆的大小,圆心决定圆的位置. .(判断对错)
6÷ ==37.5%=12: =.
=12÷ =0.25=4: = %
1÷4==4: = %= (小数)
==6﹣ = ÷= 折.
:5=72: =18:15== % .