原始社会的巨大石环主要是做什么用的？（）
A.纪念祖先
B.崇拜祖先
C.原始部落的标志
D.战争胜利的纪念
参考答案：B
The sample mean is a consistent estimator of the population mean because the:（）
A. expected value of the sample mean is equal to the population mean.
B. sampling distribution of the sample mean has the smallest variance of any other unbiased estimators of the population mean.
C. sample mean provides a more accurate estimate of the population mean as the sample size increases.
关于唐律中的刑罚适用原则，下列表述正确的有( )
A．“十恶”犯罪为“常赦所不原”
B．老年人和残疾人犯罪可减免刑罚
C．禁止以类推方法定罪量刑
D．外国人犯罪一律依照唐律处罚
