求助，改变数组一个元素的值，另一个也会跟着变，为什么？
Public Class Form1
Dim i, j, k As Integer
Private Structure str_c
Dim c() As Double
End Structure
Private Structure str_b
Dim b() As str_c
End Structure
Private a(2) As str_b
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim d As str_c
ReDim d.c(39)
For i = 0 To 39
d.c(i) = 9.9
Next
For i = 0 To 2
ReDim a(i).b(10)
For j = 0 To 10
ReDim a(i).b(j).c(39)
a(i).b(j) = d
Next
Next
For i = 0 To 2
For j = 0 To 10
For k = 0 To 39
a(i).b(j).c(k) = 10 '在这里改变a(i).b(j).c(k)的值为10，为什么a(i+1).b(j).c(k)的值也会变成10？
Next
Next
Next
End Sub
End Class
