()称为场频,也是刷新率。
A.水平刷新频率
B.垂直刷新频率
C.隔行扫描频率
D.逐行扫描频率
参考答案:B
The standard normal distribution is most completely described as a:()
A. symmetrical distribution with a mean equal to its median.
B. normal distribution with a mean of zero and a standard deviation of one.
C. distribution that exhibits zero skewness and no excess kurtosis.
在简略寿命表中,可以由一个关键指标按照一定计算公式计算出其他各项指标,这个关键指标是()。
A.尚存人数
B.年龄组死亡概率
C.生存人年数
D.生存总人年数
E.平均寿命