单选题 （共 3 题 ），每题只有一个选项正确
已知向量组 $\boldsymbol{\alpha}_{1}, \boldsymbol{\alpha}_{2}, \boldsymbol{\alpha}_{3}, \boldsymbol{\alpha}_{4}$ 线性无关, 则向量组
$\text{A.}$ $ {\alpha}_{1}+ {\alpha}_{2}, {\alpha}_{2}+ {\alpha}_{3}, {\alpha}_{3}+ {\alpha}_{4}, {\alpha}_{4}+ {\alpha}_{1}$ 线性无关.
$\text{B.}$ $ {\alpha}_{1}- {\alpha}_{2}, {\alpha}_{2}- {\alpha}_{3}, {\alpha}_{3}- {\alpha}_{4}, {\alpha}_{4}- {\alpha}_{1}$ 线性无关.
$\text{C.}$ $ {\alpha}_{1}+ {\alpha}_{2}, {\alpha}_{2}+ {\alpha}_{3}, {\alpha}_{3}+ {\alpha}_{4}, {\alpha}_{4}- {\alpha}_{1}$ 线性无关.
$\text{D.}$ $ {\alpha}_{1}+ {\alpha}_{2}, {\alpha}_{2}+ {\alpha}_{3}, {\alpha}_{3}- {\alpha}_{4}, {\alpha}_{4}- {\alpha}_{1}$ 线性无关.
设矩阵 $\boldsymbol{A}=\left(\begin{array}{cccc}1 & -3 & 1 & -2 \\ 2 & -5 & -2 & -2 \\ 0 & -4 & 5 & 1 \\ -3 & 9 & -6 & 7\end{array}\right), M_3$, 是 $\boldsymbol{A}$ 的第 3行第 $j$ 列元素的余子式 $(j=1,2,3,4)$, 则 $M_{31}+3 M_{32}-2 M_{33}+2 M_{34}=$
$\text{A.}$ 0
$\text{B.}$ 1
$\text{C.}$ $-2$.
$\text{D.}$ $-3$.
设矩阵 $\boldsymbol{A}=\left(\begin{array}{cccc}1 & -3 & 1 & -2 \\ 2 & -5 & -2 & -2 \\ 0 & -4 & 5 & 1 \\ -3 & 9 & -6 & 7\end{array}\right), M_{3 j}$ 是 $\boldsymbol{A}$ 的第 3 行第 $j$ 列元素的余子式 $(j=1,2,3,4)$, 则 $M_{31}+3 M_{32}-2 M_{33}+2 M_{34}=$
$\text{A.}$ 0
$\text{B.}$ 1
$\text{C.}$ -2
$\text{D.}$ -3