主题：二维集合怎么定义和赋值

Dim ls1 As new List(of List(Of String))
Dim ls2 As new List(Of String)
Dim ls3 As new List(Of String)
ls2.add(123)
ls2.add("abc")
ls3.add(111)

ls1.add(ls2)
ls1.add(ls3)

msgbox(ls1(0)(1))