Do you think the thief entered through the back door—No, if he had, I don’t believe he ______ theliving-room window.

The children ran out _______ after they finished their homework.

The old book there ______ some strange pictures in it. Nobody can understand them.

The report was not concrete and in a way lacked persuasion, but ______, I felt it is fair

The first use of atomic weapons was in 1945, and their power _____ increased enormously ever since. [ ]