Once he makes up his mind to do something, he will devote himself _________to it.

We didn’t know you were in trouble at that time,_____ we would have given you a hand.

As their memories decline, some old people tend to be talkative because they ______ forget what has just been said.

Honestly speaking, I would agree with Shirley, though not ______.

He is _____ tearing up what he has written and beginning over again.