106. The stone steps up to the mountain temple had been worn ______ by centuries of visitors from every part of the world.
Was it _____ she heard with her ears _____ really made her frightened?
Is this factory _____ you visited the other day?
Never _____ time come back again.
Can _____ be in the desk _____ you have put my letter?
Time should be made good use of ____ our lessons well.