招标人对已发出的招标文件进行澄清或修改时应在投标文件截止时间至少( )日前，以书面形式通知所有招标文件接收人。

A．10

B．15

C．20

D．30

单击一次命令按钮之后，下更程序代码的执行结果为______ 。
Public Sub Proc(a() As Integer)
Static i As Integer
Do
a(i) = a(i) + a(i + 1)
i=i+1
Loop While i ＜ 2
End Sub
Private Sub Command1_Cliek()
Dim m As Integer
Dim i As Integer
Dim x(10) As Integer
For i = 0 To 4
x(i) = i + 1
Next i
For i = 1 To 2
Call Proc (x)
Next i
For i = 0 To 4
Print x(i);
Next i
End Sub

A．3 4 7 5 6

B．3 5 7 4 5

C．1 2 3 4 5

D．1 2 3 5 7