‎下面代码的输出结果是（）。​‎def f(): x=198 print(x) x=9 f() print(x)​ A: 198 198 B: 198 9 C: 9 198 D: 出错

‌下面代码的输出结果是（）。‍‌def f(): global x x=198 print(x) x=9 f() print(x)‍ A: 198 198 B: 198 9 C: 9 198 D: 出错

设\( {\bf{A}} \) 为三阶矩阵，\( { { \bf{A}}^*} \)是\( {\bf{A}} \)的伴随矩阵，且\( \left| {\bf{A}} \right| = 1 \)，则\( \left| {2 { { \bf{A}}^{ - 1}} + 3 { { \bf{A}}^*}} \right| = \)______

${\bf P}(X=4)=\,$ ${\bf P}(X=3)=\,$ ${\bf P}(X=2)=\,$ ${\bf P}(X=1)=\,$______

设${\bf{r}}$是从地心指向卫星质心的矢量，则表达式____总成立。 A: ${\bf{r}} \cdot {\bf{\dot r}} = r \cdot \dot r$ B: $\left| {{\bf{r}} \times {\bf{\dot r}}} \right| = r \cdot \dot r$ C: ${\bf{r}} \cdot {\bf{\ddot r}} = r \cdot \ddot r$ D: $\left| {{\bf{r}} \times {\bf{\ddot r}}} \right| = r \cdot \ddot r$

11000110为二进制补码,该数的真值为( )。 A: +198 B: -198 C: +58 D: -58

In 1803 the United States purchased Louisiana from _____.

${\rm var}(X)=\,$ ${\bf E}[X]=\,$ ${\bf P}(X=3)=\,$ ${\bf P}(X=-2)=\,$ ${\bf P}(X=1)=\,$ ${\bf P}(X=0)=\,$______

198

${\bf P}(X=-2)=\,$ ${\bf P}(X=1)=\,$ ${\bf P}(X=0)=\,$______