He studies the subject _____. 

He found it hard for Alan to focus on his teachers for longer than five minutes, _________ if the lecture was boring. 

I can’t make a decision now. I need ____ more time to think it over.

We have done half the work so far. _____, we’ll have finished it by December. 

I sincerely regret that I have hurt your feelings, but I didn’t do it ______.