Sub Macro1()
Dim oCC As ContentControl
    Set oCC = ActiveDocument.ContentControls.Add(wdContentControlDropdownList, Selection.Range)
    With oCC
        .Title = "My List Box"
        .Tag = .Title
        .LockContentControl = False
        .SetPlaceholderText , , "Select Fruit"
        .DropdownListEntries.Add Text:=.PlaceholderText, value:=""
        .DropdownListEntries.Add Text:="Apples", value:="Apples"
        .DropdownListEntries.Add Text:="Pears", value:="Pears"
        .DropdownListEntries.Add Text:="Plums", value:="Plums"
        .DropdownListEntries.Add Text:="Grapes", value:="Grapes"
    End With
    Set oCC = Nothing
End Sub