He found it hard for Alan to focus on his teachers for longer than five minutes, _________ if the lecture was boring.
He _____ more than thirty.
A computer _____ think for itself; it must be told what to do.
You _____ to eat if you don’t feel like it.
How _____ you say that you really understand the whole story if you have covered only part of the article?
It has been announced that candidates _____ remain in their seats until all the papers have been collected.