对于n元齐次线性方程组，如果其系数矩阵的秩r小于未知量的个数n, 则方程组的基础解系存在，且含（）个解向量. A: r B: n C: n-r D: r-n

球对称带电黑洞(R-N黑洞)有内、外两个视界面。外视界, 内视界,中心r = 0...nanas/latex/p/649042

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

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

若设变压器初、次级线圈的匝比为N=N A: R=NR B: R=NR C: R=R/N D: R=R/N

S为细胞质不育基因，N为细胞质可育基因，r为细胞核不育基因，R为细胞核可育基因。下列杂交何者可产生雄性不育系（ ）。 A: S(r r) × N(RR) B: S(r r) × N(r r) C: N(R r) × S(r r) D: N(r r) × N(r r)

命题“∀x∈R，∃n∈N*，使得n≥x2”的否定形式是（） A: ∀x∈R，∃n∈N*，使得n2 B: ∀x∈R，∀n∈N*，使得n2 C: ∃x∈R，∃n∈N*，使得n2 D: ∃x∈R，∀n∈N*，使得n2

设\({A_{m \times n}},{B_{n \times k}}\),若\(AB = O\),则下列选项正确的是（ ） A: \(R(A) + R(B) = n\) B: \(R(A) + R(B) \le n\) C: \(R(A) + R(B) \ge n\) D: \(R(A) + R(B) &gt; n\)

n×n齐次线性方程组存在非零解的充要条件是： A: r(A)=n B: r(A)&gt;n C: r(A)≤n D: r(A)

下列计算最大公约数的递归过程，正确的是___________。 A: Sub gcd(ByVal m%, ByVal n%) Dim r% r = m n If r = 0 Then gcd = n Else gcd = gcd(n, r) End If End Sub B: Sub gcd(ByVal m%, ByVal n%) Dim r% r = m Mod n If r = 0 Then gcd = n Else gcd = gcd(n, r) End If End Sub C: Function gcd%(ByVal m%, ByVal n%) Dim r% r = m n If r = 0 Then gcd = n Else gcd = gcd(n, r) End If End Function D: Function gcd%(ByVal m%, ByVal n%) Dim r% r = m Mod n If r = 0 Then gcd = n Else gcd = gcd(n, r) End If End Function