The book has been translated into thirty languages since it ______ on the market in 1973.
Your suggestion sounds interesting, but they need a (n) __________ one to get out of the mess.
The headmaster has retired but no one knows who will __________ him in the post.
Progress __________ so far very good and we are sure that the work will be finished on time.
Before you make a plan, you'd better __________ the advantages and disadvantages of it.
—You can't imagine __________ fantastic fun web chatting is.—Really? But it may cause a lot of trouble sometimes.