IfA=211,B=130,thenA+B=(_);

The matrix A is[img=44x19]1803b6ad8347a80.png[/img]. If the eqaution Ax=0 has only the trivial solution , thenA is invertible.

If3a=8band15b=4c,thena/c=______. A: 4/5 B: 8/15 C: 32/45 D: 15/18 E: 11/9

Complete the dialogues with the words and expressions given in the box.find out if Mr. Smith could see me what can I do for you he is free thenA: Good morning. Is Mr. Smith in?B: No, I’m afraid not. But _____________ ? I’m Mrs. Smith.A: I’m calling to _______________at 3 tomorrow afternoon? I have some problems to discuss with him.B: Yes, __________________ . I’ll tell him you’ll be coming.

在窗体上画一个命令按钮(其Name属性为Commandl)，然后编写如下代码： Private Sub Commandl_Click() Dima(5) Fori=0 To 4 A(i)=i+1 t=i+1 If t=3 Then Print a(i) A(t-1)=a(i-2) Else A(t)=a(i) End If Ifi=3 Thena(i+1)=a(t-4) A(4)=1 Printa(i) NextI End Sub 程序运行后，单击命令按钮，输出结果是上______。

Whichtwowordsareclosestinmeaning?<br/><b>cycle</b><b>，</b><b>hawk</b><b>，</b><b>convey</b><b>，</b><b>extort</b><b>，</b><b>peddle</b><b>，</b><b>summon</b>

设A{a,b}，则P(A)×A = (   )。 A: A B: P（A） C: {<Φ,a>,<Φ,b>,<{a},a>,<{a},b>,<{b},a>,<{b},b>,<A,a>,<A,b>} D: {<a,,Φ,>,<b,,Φ,>,<a,{a}>,<b,{a}>,<a,{b}>,<b,{b}>,<a,A>,<b,A>}

以下哪段代码可以将A,B的值互换（） A: A=A^B; B=A^B;A=A^B B: A= A^B;A=A^B;B=A^B C: B= A^B; B=A^B; A=A^B D: B=A^B; A= A^B; A= A^B

若集合A={a，b}，B={ a，b，{ a，b }}，则（）。 A: A⊆B，且A∈B B: A∈B，且B⊆A C: A⊈B，且A∉B D: A∉B，且A⊈B

设论域D={a,b}，与公式[img=504x85]17d6234b6469e12.png[/img]等价的命题公式是（ ） A: (A（a）∧A（b）) → (B（a）∧B（b）) B: (A（a）→B（a）)∨(A（b）→B（b）) C: (A（a）∨A（b）) → (B（a）∨B（b）) D: (A（a）→B（a）)∧(A（b）→B（b）)