设A是n阶矩阵,下列不是命题“0是矩阵A的特征值”的充分必要条件的是().
A的行向量组线性相关
B. 方程组AX=0有非零解
C. 对任何非零向量b,方程组Ax=b都没有唯一解
D. 存在自然数k,使得Ak=O
The word "avert" in the passage is closest in meaning to
A. place down.
B. turn away.
C. hide out.
D. move back.
设函数f(x)在x=0处连续,则下列命题错误的是().
The word "rigorous" in the passage is closest in meaning to
A. disorderly.
B. strict.
C. traditional.
D. irrational.