He tried his best to solve the problem, __________ difficult it was.
---Why didn’t Tom give you one of his paintings? ---I didn’t want one, but he would have given me one if I _________.
---When did you learn the news that Obama made a trip to Canada as President? --- _________ was on my return.
Joined by their friends, Troy and Gabriella staged a musical _______ their experiences, hopes and fears about the future.
You _______ late for yesterday’s class meeting, as it was so important.
Why do we have to ________ Joan’s selfish behavior? She should learn to care for others.