The engineers made two big plans for the dam, ____ was never put in force.
----What do you suppose made her worried ? ----______a gold ring .
----Why ? Where’s the key to the meeting room? ----Dear me! You ______it in the taxi!
He has read lots of books,_____that he is still young.
Some of the students have already learned enough English to _______a conversation with an English speaker.
It was not until dark _____he found _____he thought was the correct way to solve the problem.