1.When I opened the door, the lesson(to begin)...and the teacher(to explain)...something to the class.
2.I(to clean)...the carpet, when the dog(to come)...and(to share)...himself.
3. When the bell rang, the children(to run)..info the classroom and (to take)...their seats.
4. We (to have)...a good long holiday after we (to do)... all the work.
5.Before we(to take)...the boy to the theatre , he (never to see)...a play.
6.By the time we(to arrive)...,the party (to finish)
7.When I (to get)...to the playgroung my friend... already(to leave)...so I (not to see)...him that day.
8.What you (to do)...,when I (to call)...you? I(to cook)... .