某单因子试验，因子A取r个水平，做m次重复试验，总的自由度为（）。 A: rm B: rm-1 C: r+m-1 D: r-m

实对称阵`\A`的秩等于`\r`，又它有`\m`个负的特征值，则它的符号差为 （ ） A: `\r-m` B: `\m-r` C: `\r-2m` D: `\m-2r`

设A为m×n矩阵，B为n×m矩阵，且m＞n，令r(AB)=r，则( )。 A: r＞m B: r=m C: r＜m D: r≥m

求给定自然数m和n的最大公约数。请完善程序。 Private Sub Command1_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r Do r = m Mod n m = n n = r Loop Until__________ Text3.Text = m End Sub Private Sub Command2_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r r = m Mod n Do Until _______ m = n n = r r = m Mod n Loop Text3.Text =____ End Sub Private Sub Command3_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r Do r = m Mod n m = n n = r Loop While________ Text3.Text =______ End Sub Private Sub Command4_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r r = m Mod n Do While______ m = n n = r r = m Mod n Loop Text3.Text =____ End Sube73f1fd63959cc8362d8c82d419c2353.png

设A是m×n矩阵，B是n×m矩阵，E为m阶单位矩阵，若AB＝E，则（）。 A: r（A）＝m，r（B）＝m B: r（A）＝m，r（B）＝n C: r（A）＝n，r（B）＝m D: r（A）＝n，r（B）＝n

设A为m×n矩阵，B为n×m矩阵，E为m阶单位矩阵，若AB=E，则（）. A: r（A）=m，r（B）=m B: r（A）=m，r（B）=n C: r（A）=n，r（B）=m D: r（A）=n，r（B）=n

设\(A\)为\(m \times n\)矩阵，\(B\)为\(n \times m\)矩阵，\(E\)为 \(m\)阶单位矩阵，若\(AB=E\)，则 A: \(R(A)=m, R(B)=m\) B: \(R(A)=m, R(B)=n\) C: \(R(A)=n, R(B)=m\) D: \(R(A)=n, R(B)=n\)

设A为m×n矩阵，B为n×，n矩阵，若AB=E，则( ) A: r(A)=m，r(B)=m B: r(A)=m，r(B)=n C: r(A)=n,r(B)=m D: r(A)=n，r(B)=n

设A是m×n矩阵,B是n×m阶矩阵,E是m阶单位矩阵,若AB=E,则( ) A: R(A)=m,R( B: =mB、 R(A)=m,R(B)=n C: R(A)=n,R(B)=m D: R(A)=n,R(B)=n

设A为m×n阶矩阵，B为n×m阶矩阵，且m>n，令r(AB)=r，则( )． A: r>m B: r=m C: rD．r≥m