【判断题】设 A 是 m ́n 矩阵,齐次线性方程组 Ax = 0 有非零解,其基础解系中有r个向量,则R(A) = n-r。
【单选题】可使针感向一定方向传导的行针辅助手法的是
【单选题】The impact of Jack Lindsay's ideological attitudes on his literary success was
C.
limited but indivisible.
D.
obscure in net effect.
【单选题】可使针感向一定方向传导的行针辅助手法的是
【单选题】可使针感向一定方向传导的行针辅助手法是()。
【单选题】In Lindsay's time, ________.
A.
there was a great improvement in race relations
B.
black people were still looked down upon
C.
the Georgia State government encouraged black students to work for it
D.
it was impossible for blacks to enter famous universities
【单选题】According to the passage, Lindsay's purpose in life was to______.
A.
become a famous lawyer
C.
get another scholarship to study abroad
D.
be elected to political office at the local level
【单选题】According to the passage, Lindsay's purpose in life was to _________.
A.
become a famous lawyer
B.
be elected to political office at the local level
C.
get another scholarship to study abroad
【判断题】设 A 是 m ́n 矩阵,且 R(A) = r < n,则,齐次线性方程组 Ax=O 存在基础解系,且基础解系中有 n-r 个线性无关的解向量.