Sub Macro1()
Dim oPara As Paragraph
    For Each oPara In ActiveDocument.Paragraphs
        If InStr(1, oPara.Range.Text, "WAS") = 0 And _
           InStr(1, oPara.Range.Text, "WERE") = 0 Then
            oPara.Range.Delete
        End If
    Next oPara
End Sub