.Be careful about the news on red fire ants—____measures to prevent the possible spread of them.
The gentleman ______ you told me yesterday proved to be a thief.
It was ______ computer games that cost the boy a lot of time that he ought to have spent on his lessons.
______ a reply, he decided to write again.
The first textbooks ______ for teaching English as a foreign language came out in the 16th century.
Most common people desired that more attention _______ public opinion.