A better plan was _____ by the headmaster.
Officials believe that more than one person _____ for the big fire.
While cleaning the snow on the road, _________.
--- Did you understand what the teacher said ? ---Yes! She explained the text in detail to make her lessons __________.
We appreciate the notice that you_____ the mistakes we made in newspapers.
He was __ with the results of the exam, which can be seen from his __ smile.