【单选题】向量函数组 在区间 I 上线性相关的( )条件是在区间 I 上它们的朗斯基行列式 .
【单选题】向量函数组在区间 I上线性相关的( )是在区间 I上它们的朗斯基行列式 。
【单选题】What did the woman think of Jack?
A.
S. he thought him a good man.
B.
She thought Jack had done well in mending the umbrella for her.
C.
She didn't think Jack was a good man.
【单选题】由于现阶段网络保险发展还处于起步阶段,下列各项中,不构成网络保险的优势的是()