I think at the beginning of each book a __________ introduction to it is necessary.
. Having been attacked by terrorists, _________.
. Johnson ___________ for 5 years for some reasons when he was young.
. ________________ be sent to work here?
. —— The plane will take off in half an hour. I’m afraid I must be going now. —OK. ________.
. The boy often gives a satisfactory answer to the teacher’s question, _____ just a minute. So he’s usually the teacher’s pet.