一个有效的工具变量应满足如下两个条件 A: corr(Zi, Xi) = 0 and corr(Zi, ui) ≠ 0 B: corr(Zi, Xi) = 0 and corr(Zi, ui) = 0. C: corr(Zi, Xi) ≠ 0 and corr(Zi, ui) = 0 D: corr(Zi, Xi) ≠ 0 and corr(Zi, ui) ≠ 0

已知某线性相位FIR滤波器的零点Zi,则下面哪些点仍是该滤波器的零点 A: Zi* B: 1/Zi* C: 1/Zi D: 0

Who is the representative of Confucians?‎ A: Mencius B: Lao Zi C: Xun Zi D: Confucious

费用支出最高的企业是（）。 A: 57 B: 57 C: 57 D: 57

Lao Zi was known as the Chinese Nietzsche.

Zi means Ziwei Star and Ziwei Star is __________________________________.

___ talks about Confucius like this: Confucius is a sage of being appropriate to the time; Confucius is a man of great attainments. A: Mencius B: Xun Zi C: Mo Zi

改进dh参数di参数含义为以下哪个选项？ A: 沿着Zi轴，从Xi-1移动到Xi的距离 B: 沿着Xi-1轴，从Zi-1旋转到Zi的距离 C: 绕着Zi轴，从Xi-1旋转到Xi的角度 D: 绕着Xi-1轴，从Zi-1移动到Zi的角度

【单选题】如下语句的输出分别是什么？printf ("%d %d ", 12, 12 + 45);printf ("%d,%d ", 12, 12 + 45);printf ("%d %d ", 12, 12 + 45);printf ("%d%d ", 12, 12 + 45);printf ("%d.%d ", 12, 12 + 45); A. 12 57 12,57 12 57 12 57 12.57 B. 12 57 12,57 12 57 12 57 12.57 C. 12 57 12,57 12 57 1257 12.57 D. 12 57 12,57 12 57 1257 12.57

西班牙语中，不存在ze、zi这种拼写方式。