—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
I was almost asleep last night when I suddenly heard someone ______ at the door.
It wasn't such a good job ______ she had read about in the advertisement.
She didn't go to the party last night, ______ she had to finish her term paper.
It's my great honor ______ to give a speech at the opening ceremony.
Once more I have to leave Beijing, ______ I have been living for eight years.