设8元齐次线性方程组AX=0的解向量所组成的向量组的最大无关向量组含5个向量，则矩阵A的秩为( )。
A．2
B．3
C．5
D．7
参考答案：B
---- __________ is it from Sunshine Town to the center of Beijing?
---- It’s about 20 kilometers ________ our school.
A．How often , far from
B．How long, away from
C．How soon, far away from
D．How far, away from
Amy and Maria are in the same______,but in different______. [ ]
A. grade; class
B. grade; classes
C. grades; class
D. grades; classes
