Employees that place a heavy emphasis on the and of their benefits programs as key competitive differenciators are characterized as progressive.
A. richness
B. duration
C. cost
D. diversity
Online chat is a way of communicating by sending text messages to people in the same chat-room real-time.
A. in
B. of
C. by
D. at
长征三号系列是我国自行研制的三级运载火箭,具有如下特点()
A. 运载能力大
B. 适用性强
C. 具备空中二次点火
D. 节能减排
关于回归系数b,下面正确的说法是
A. b也可以反映X和Y之间的关系强度
B. 回归系数不解释两变量间的因果关系
C. b公式中的两个变量都是随机的
D. b的取值在1和-1之间