vb.net中split的疑問

Public Class SplitTest    Public Shared Sub Main()        Dim words As String = "This is a list of words, with: a bit of punctuation" + _                              vbTab + "and a tab character."        Dim split As String() = words.Split(New [Char]() {" "c, ","c, "."c, ":"c, CChar(vbTab) })        For Each s As String In  split            If s.Trim() <> "" Then                Console.WriteLine(s)            End If        Next s    End Sub 'MainEnd Class 'SplitTest' The example displays the following output to the console:'       This'       is'       a'       list'       of'       words'       with'       a'       bit'       of'       punctuation'       and'       a'       tab'       character

兩個問題：

1、dim  a( )  as string
      dim   a     as string( )
     兩者有啥區別？

2、split後面的成員列表是分隔字元的列表嗎？只見過一個分隔關鍵字的，沒見過多個的，有知道的嗎？
        

    {" "c, ","c, "."c, ":"c, CChar(vbTab) }

         這幾個成員是什麼意思？   其中的c又是什麼意思？