He ________ being given a receipt for the bill he had paid.

When I telephoned the headmaster, his secretary told me to ________ on as he was talking to someone else.

Then, all of a ________ there was an explosion and the lights went out.

Good parents should ________ for their children.

When the house is not occupied, it is ________.

When the house is not occupied, it is ________.

My mother got home ________ ago.

Give me the message to ________ is at the desk!

In a week's time you ________ in Boston for a year.

A: Are you leaving?
B: Yes, but I wish I ________ to go.