“统计”一词含义有()。

120型制动机置急充风位，待副风缸充至定压后保压，置紧急排风阀开启位，制动管减压() 前，制动机须发生紧急制动作用。

对借款人的信用分析有

影响学习效率的直接因素是()

Scholars from the University of Kansas published the results of a decade_long Study recently,suggesting that sending, children to pre-school at the age of 4 comes too late to_educational drawbacks at home.