I don't understand how this can be dozing off, as well as sleeping. I'm really confused about this whole lesson, as things like 'sleeping' are different than 'dozing off'. In other sections the correct answer is given as 'about to ____' where I'm pretty sure the course notes said that this is the progressive, and the person is already doing the indicated thing. I'm about to write is different than I am writing. Can anyone help here?