下面的程序代码是通过函数求出二个整数型变量a、b中的较大值，其中所定义的函数名是（   ）
Function max(a, b As Integer) As Integer
If a > b Then max = a  Else  max = b
End Function
Private Sub Command1_Click()
Dim a As Integer, b As Integer, s as integer
a =" Val(Text1.Text):" b = Val(Text2.Text)
s =" max(a," b)
Text3.Text = s
End Sub

A．Command1_Click

B．function

C．max

D．max(a, b As Integer)

布尔型变量的默认值是

A．0

B．-1

C．FALSE

D．TRUE

在VisuA.l B.A.siC.中，下列能作为变量名的是（ ）
A.5A. B.A.5 C.if   D.D.im

如下流程图所描述的算法实现的功能是（）

A．交换a,b两数的值

B．求a,b两数的最大值

C．求a,b两数的最小值

D．以上都不对

（加试题）小王设计了一个算法试图求出平面坐标系中最左点出发，从左往右途经所有点到达最右点的路径值和，编写了一个VB程序功能如下：在文本框Text1中输入需随机生成的坐标点数量，单击“生成”按钮Command1后，在列表框List1中生成相应数量的坐标点（坐标值为大于等于1小于10的实数 ，保留一位小数），在文本框Text2中输出路径值。程序界面如图所示。

实现上述功能的VB程序如下，但划线部分代码有错，请改正。
Private Sub Command1_Click()
Dim x(1 To 100) As Single, y(1 To 100) As Single
Dim tmp As Single, length As Single, sum As Single, x1 As Single, y1 As Single
Dim i As Integer, j As Integer, k As Integer
Randomize 
List1.Clear
k = Val(Text1.Text)
For i = 1 To k
x(i) = Int(Rnd * 90) / 10 + 1
y(i) = Int(Rnd * 90) / 10 + 1
List1.AddItem "X:" + Str(x(i)) + "   " + "Y:" + Str(y(i))
Next i
For i = 1 To k - 1
For j = 1 To k - i
If x(j) > x(j + 1) Then
x(i)=x(i) + x(j)
x(j) = x(i) - x(j)
 x(j) = x(i) + x(j)   答：________________
tmp = y(j)
y(j) = y(j + 1)
y(j + 1) = tmp
End If
Next j
Next i
sum = 0: length = 0
For i = 1 To k - 1
 x1 = (x(i) - x(1)) ^ 2     答:______________    
'变量y1计算方法同x1，代码略
length = Sqr(x1 + y1)
sum = sum + length
Next i
Text2.Text = Str(Int(sum * 10) / 10)
End Sub