I called the airline to ___ my flight reservation a week before I left for Canada.
Education is a lifelong process, ____ starting long before the start of schooling.
—Shall we go out for a walk? —I'm afraid not.We can't go out ___ our work is being done.
___ we have overlooked, however, is that there is no one answer to this question.
—What a shame! —Yes, I ____ his not doing it, but in vain.
Maybe you could be an inventor—maybe even good enough to _____ the next iPhone or the new medicine for cancer.