一根绳子先剪去全长的,再剪去米,两次剪去的长度一定是不相等的. .(判断对错)
= :35=5:7= ÷21=.
== ÷20=6: = %= 折.
÷15=0.8== %= 折.
1﹣1× =0÷ == : =75%
: =0.125= %==.