How was ______ they discoveredthe entrance to the underground palace—Totally by chance.

_____ I hand in my report as soon as the class is over? — No, you needn’t. Anytime this week is okay. [ ]

Who’ssinging in the next room — It ______ beMary. She ______ New York.

Yahoo recently announced to ________ 2,000 employees, about 14% of the company’s workforce, aiming to save $375 million annually.

You may choose one from _________ was left.