By the time you have finished this book, your meal ______ cold.
The teacher __________ his students __________ five groups.
The police are trying to find out the __________ of the woman killed in the traffic accident.
—Who knows where Terry is? —The reason __________ Terry is absent is __________ his father had an accident.
__________ you have finished this programme, can you talk about our plan for holiday trip now?
I was about to leave __________ someone knocked at the door.