'can’t'. (said with a shake of the head and an air of finality)
'that’s the dumbest thing i have ever heard'.
'yeah, but if you did that….' (poses an extreme or unlikely disaster case)
'we have already tried that – years ago'.
'we have done that all right so far; why do we need that?'
'i don’t see anything wrong with the way we are doing it now'.
'that doesn’t sound too practical'.
'we have never done anything like that before'.
'let’s get back to reality'.
'we have got deadlines to meet; we don’t have time to consider that'.
'it’s not in the budget'.
'are you kidding?'.
'let’s not go off on a tangent'.
'where do you get these weird ideas?'.