【单选题】设Z+={x|x【图片】Z【图片】x>0},这里“【图片】”表示求两个数的最小公倍数,则该运算的幺元是( )
【简答题】c : n. the process of giving all your attention to sth.
【单选题】VAR模型如下【图片】【图片】【图片】【图片】【图片】【图片】假设x对y有预测作用,z对y没有预测作用,下面的表述正确的是?
A.
b 21 = d 21 =0 不显著, b 32 = d 32 =0 显著
B.
b 21 = d 21 =0 显著, b 23 = d 23 =0 不显著
C.
b 21 = d 21 =0 不显著, b 23 = d 23 =0 显著
D.
b 21 = d 21 =0 显著, b 32 = d 32 =0 不显著
【简答题】n. [C] the place where sth. is or where sth. happens, and the general environment 背景;环境
【简答题】n. [C] a way of thinking about sth.
【简答题】in______y n. the state of not being as good as sb.\ sth. else