____ is known to us all that the old scientist , for ____ life was hard in the past, still works hard in his eighties.
It was not until dark he found he thought was the correct way to solve the problem.
The students are listening to the teacher with their eyes the blackboard.
It was in this house ______ he heard some strange sounds.
----Where did you find the wallet? ---- It was at the stadium_____I played football.
Faced with a bill for $ 10,000, ________________ .