Maybe he ______ to stick to his ridiculous thought at the moment, but, trust me, he will change his mind tomorrow morning.
—What was it that caused the party to be put off? —________ the invitations.
Who ________ that played a trick on the new English teacher?
—Where did you pick up the stamp? —It was at the post office ________ we worked in the summer vacation.
—Was it by cutting down staff ________ she saved the firm? —No,it was by improving work efficiency.
Is it that you often play computer games ________ worries your parents?