_____ this something, still unseen, they gave the name radium.
______ 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.
Beijing isn’t what it used to be. The last decade _______ great changes in the city images.
I’m not used to the way you speak to me. _______, I don’t want to continue the conversation.