单项选择题
A.40℃ B.50℃ C.60℃ D.80℃
A.10倍 B.15倍 C.2~3倍 C.20倍
A.30~40孔/cm2 B.40~50孔/cm2 C.50~60孔/cm2 D.60~70孔/cm2