用80粒种子做发芽实验,未发芽的有4粒,发芽率是 .
÷8==0.375=9÷ =; 填质数:21= + ; = × .
= %=2÷ =四成.
14÷ == ÷ = (填小数)
= ÷12= (填小数).
12÷ =0.75=.