把6米长的钢筋锯成6段,如果锯两段需2分钟,共需 分钟.
: =15÷ == (填小数).
= : ==6÷ .
0.6==18÷ = :10= %
:8=0.8: =0.2= .
8: ===2.4÷ = (填小数)