— Will Miss Wang attend our meeting tomorrow? 

— It will not be _____ so. [ ]

A. commonly

B. necessarily

C. usually

D. extremely

按比例抽样方案的特点有（）

A.简明易懂

B.易于掌握

C.小批严，大批松

D.不能回答检验结果的可靠程度

E.样本大小与质量波动程度无关