After a day's hard labor on the farm, my parents came home late, __________.
Sometimes children are _______ enough to create ______ stories.
The professor _______ to walk out of the office when one of his students came in.
Look, the little girl is dancing as if she ______ a little bird.
The teacher told me that the earth _______ round.
----Jack hasn’t got a job yet, has he? ---- Oh yes, in fact, he has been ________ for two weeks.