By the time a child is five, he _______ hundreds of hours of television.
______ from what he said, he must be the thief who has stolen the car.
They were surprised that a child could work out the problem ______ they themselves couldn’t.
--- I hear Jane has gone to the Holy Island for her holiday. --- Oh, how nice! Do you know when she ______ ?
The factory was built in a secret place, around _____ were high mountains.
The teachers were discussing the research project that they would like to see _____ in the coming holiday.