David, you said you would work harder the next term.–That’s for sure. I am a man of my word.

He has devoted most of his time and energy _______ a cure for the disease.

It’s worth downloading, because it’s free and doesn’t__________ a lot of disk space.

It’s not polite to _______ others.

I have a word with you—- Sorry, I am busy ______. Shall we doit later