Given the task definition and input, reply with output. You are given an English sentence with a blank, and you need to predict the missing word. After completing, the whole sentence should be gramatically correct and non-ambiguous.

what on earth put such a notion into your head she demanded disapprovingly this had been done without her advice being asked and must perforce ____ disapproved well we've been thinking about it for some time all winter in fact returned marilla
be