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乙苯脱氢生成苯乙烯 C6H5C2H5（g）＝ C6H5CH=CH2（g）+ H2（g） 是吸热反应，通入过热水蒸气（不参加反应）可以提高苯乙烯产率，为什么？
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（13）单击命令按钮时，下列程度的执行结果是 Private Sub Command1_Click() Dim a As Integer,b As Integer,c As Integer a=2:b=4:c=6 Call S2(a,b) Print"a=";a;"b=";b;"c=";c; End Sub Private Sub S1(x As Integer,y As Integer) Dim c As Integer x=2*x:y=y+2:e=x+y End Sub Sub S2(x As Integer,By Val y As Integer) Dim e As Integer x=2*x:y=y+2:e=x+y End Sub A.a=4 b=6 c=6 B.a=8 b=6 c=6 a=4 b=6 c=6 a=8 b=6 c=6 C.a=4 b=6 c=6 D.a=8 b=6 c=6 a=8 b=6 c=6 a=4 b=6 c=6
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运行以下程序后，输出结果为_____________。 Private Sub Command1_Click() a=1:b=2:c=3 Call test(a,b+3,(c)) Print "main:";a;b;c End Sub Private Function test(p,m,n) p=p+1:m=m+1:n=n+1 Print "sub:";p;m;n End Function：A. sub:2 6 4 main:1 2 3B. sub:2 6 4 main:2 2 3C. sub:2 6 4 main:2 6 4D. sub:2 6 4 main:1 6 4
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阅读如下程序, a = 1: b = 2: plus S, a, b: Print S:不能使其输出结果为3的plus过程为( )。
A、Sub plus(sum, a , b ): sum = a + b: End SubB、Sub plus(ByVal sum , a , b ): sum = a + b: End SubC、Sub plus(sum , ByVal a, ByVal b ): sum = a + b: End SubD、Sub plus(sum , ByRef a , ByRef b ): sum = a + b: End Sub
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在窗体中添加一个名称为Command1的命令按钮，然后编写如下程序： Public x As Integer Private Sub Command1_Click() x=10 Call s1 Call s2 MSgBox x End Sub Private Sub s1() x=x＋20 End Sub Private Sub s2() Dim x As Integer x=X＋20 End Sub 窗体打开运行后，单击命令按钮，则消息框的输出结果为______。A．10B．30C．40D．50
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下面程序的输出结果是( )。 #include"stdio.h" int sub(int m) { static a=4; a+=m; return a; } void main() { int i=2,j=1,k; k=sub(i); k=sub(j); printf("%d",k); }A．6B．7C．8D．9
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单击命令按钮时，下列程序段的执行结果为( )。 Private Sub Command1_Click() Dim a As Integer, b As Integer, c As Integer a-2:b=4:c=6 Call S1(a,b)Print "a="; a; "b="; b; "c="; c Call S2(a,b)Print "a ="; a; "b="; b; "c="; c; End Sub Private Sub S1(x As Integer, y As Integer) Dim c As Integer x=2*x:y=y+2:c=x+y End Sub Sub S2(x As Integer, ByVal y As Integer) Dim e As Integer x=2*x:y=y+2:e=x+y End SubA．a=4 b=6 c=6 a=4 b=6 c=6B．a=8 b=6 c=6 a=8 b=6 c=6C．a=4 b=6 c=6 a=8 b=6 c=6D．a=8 b=6 c=6 a=4 b=6 c=6
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单击命令按钮时，下列程度段的执行结果为( )。 Private Sub Command1_Click() Dim a As Integer, b As Integer, c As Integer a=2:b=4:c=6 Call S1(a,B) Print "a="; a; "b="; b; "c="; c Call S2(a,B) Print "a ="; a; "b ="; b; "c="; c; End Sub Private Sub S1(x As Integer, y As Integer) Dim c As Integer x=2*x:y=y+2:c=x+y End Sub Sub S2(x As Integer, ByVal y As Integer) Dim e As Integer x=2*x:y=y+2:c=x+y End SubA．a=4 b=6 e=6 a=4 b=6 e=6B．a=8 b=6 c=6 a=8 b=6 c=6C．a=4 b=6 e=6 a=8 b=6 e=6D．a=8 b=6 c=6 a=4 b=6 c=6
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编写如下事件过程： Private sub sub1 (ByVal x1 As String, y1 As String) Dim xt As String Dim i As Integer i = Len(x1) Do While i＞= 1 xt = xt + Mid(x1, i, 1) i=i-1 Loop y1 = xt End Sub Private Sub Form. Click() Dim s1 As String, s2 As String s1= "teacher" sub1 s1, s2 Print s2 End Sub 程序运行后，单击窗体，则窗体上显示的内容是A．rehcaetB．tahreeeC．themeeD．eerthea
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写出程序运行的结果Public class BasePublic virtual string Hello() {return “Base”;}Public class Sub:BasePublic override string Hello() {return “Sub”;}1. Base b = new Base(); b.Hello;2. Sub s = new Sub(); s.Hello;3. Base b = new Sub (); b.Hello;4. Sub s = new Base(); s.Hello;
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下面程序的输出结果是。 Private Sub Commandl_Click ch$=“ABCDEF” proc ch：Print ch End Sub Private Sub proc(ch As Stnng) s=“” For k=Len(ch) TO 1 Step -1 s=sMid(ch，k，1) Next k ch=s End Sub A．ABCDEF B．FEDCBA C．A D．F
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在窗体中添加一个名称为Commandl的命令按钮，然后编写如下程序： Public x As Integer Private Sub Commandl_click() x＝10 Call s 1 Call s 2 MsgBOx x End Sub Pfivate Sub s1() x＝x+20 End Sub Private SubA．10B．30C．40D．50
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编写如下事件过程： Option Base 1 Private Sub Form Click() Dim x1()As Integer Dim i As Integer Dim s As Integer ReDim x1(3) For i = 1 To UBound(x1) x1(i)=i + 1 Next i Call sub1(x1) For i = 1 To UBound(x1) s = s + x1(i) Next i Print s End Sub Private Sub sub1(n()As Integer) Dim i As Integer ReDim Preserve n(5) For i = 3 To 5 n(i)=n(i-1)*2 Next i End Sub 程序运行后，单击窗体，则窗体上显示的内容是A．6B．12C．24D．47
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在窗体中添加一个命令按钮,编写如下程序:Private Sub Sub1(p,m,n)p=p+1:m=m+1:n=n+1Print "sub1:";p;m;nEnd SubPrivate Sub Command1_Click()a1=1:b=2:c1=3Call Sub1(a,b1+3,c1)Print"Main:";a1;b1;c1End Sub程序运行后,输出结果为A．Sub: 2 6 4 Main: 2 6 4B．Sub: 2 6 4 Main: 2 6 4C．Sub: 2 6 4 Main: 1 2 3D．Sub: 2 6 4 Main: 2 2 3
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在窗体中添加一个命令按钮，编写如下程序： Private Sub Sub1(p，m，n) p=p+1：m=m+1：n=n+1 Print "sub1："；p；m；n End Sub Private Sub Command1_Click() a1=1：b=2：c1=3 Call Sub1(a，b1+3，c1) Print"Main："；a1；b1；c1 End Sub 程序运行后，输出结果为A．Sub： 2 6 4 Main： 2 6 4B．Sub： 2 6 4 Main： 2 6 4C．Sub： 2 6 4 Main： 1 2 3D．Sub： 2 6 4 Main： 2 2 3
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单选题煤矿井下的有害气体主要是由（）、CO2、H2S、NO2、H2、NH3气体组成。A
COB
pCHsub4/sub、SOsub2/sub/pC
pSOsub2/sub、CO/pD
pCO、CHsub4/sub、SOsub2/sub/p
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填空题s=”this is the mainstring”，sub=”string”，strindex（s，sub）是（）
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