Scientists say it may be five or six years _______ it is possible to test this medicine on human patients.
Their belief is proved by the fact that the death penalty prevents murder.
What he said at the meeting referred to _______ he was interested in the project.
She must face up to _______ she is no longer young.
They knew nothing about ______ he was a thief.
We were all worried over _______ you were sick.