Teaching is a sort of work that ___ a high level of patience, determination and devotion.
________ is to do good all one's life and never do anything bad.
They would have fixed the telephone yesterday _________ it was a holiday.
It's uncertain ________ the experiment is worth doing.
Do you know ________ he expects will give us a talk
He insisted that he ________ in good health and _______ to work there.