Deleting Rows and Columns Throughout All Worksheets

Option Explicit

Sub Test1()
    Dim SH As Worksheet
    Application.ScreenUpdating = False
        For Each SH In ThisWorkbook.Sheets
            With SH
              .Rows("1:3").Delete
              Union(.Columns("A:B"), .Columns("G")).Delete
              .Cells.UnMerge
            End With
        Next
    Application.ScreenUpdating = True
End Sub