如图中,直线a叫做直线b的 ,点O叫做 .
3:8=24÷ = %
:10== ÷20= %=0.7=.
= ÷ === (小数)= (百分数)= (成数)
0.16==2÷ =8: = %
0.75==6÷( )=12:( )=( )%