a single word can change the meaning of a sentence, a single sentence can change the meaning of a paragraph.
John was given the same suitcase his father and grandfather __________ with them to school.
Mary went to the box office at lunch time, but all the tickets __________ out.
It took me a long time before I was able to fully appreciate what they __________ for me.
—Were you surprised by the ending of the film?—No. I __________ the book, so I already knew the story.
Tom was about to close the window __________ his attention was caught by a bird.