Stop killing this kind of birds! They _______. [ ]

I don’t believe we _______ before —Well, I saw you once at a party, but we ______ introduced

I beg your pardon? —Your mind must be ________ when I was speaking, wasn’t it?

Anyone providing information which leads to the recovery of the painting will be ________.

To finish the work on time, we’ll have to work____ hours a day.