粒径分布
参考答案：
不同粒径范围内的颗粒的个数（或质量或表面积）所占的比例。
— Jack, I lost your ball at school. I suppose I should pay for it.
— Oh. ______. It was just an old ball anyway. [ ]
A. Take it easy
B. By no means
C. You got it
D. Forget it
清洁区、非清洁区使用的工作服可一次清洗
