单项选择题
A.25-30%,40-70%B.30-35%,40-70%C.20-30%,30-35%D.40-70%,25-30%
A.1小时,1B.6小时,2C.3小时,1D.1小时,2
A.1小时,1.8B.3小时,1.5C.3小时,2.0D.1小时,2.0