. — Did the accident happen in ____ summer? — Yes, I remember it happened in ____ summer of .
The radio set __ _ last week has been out of order.
He is a man of great knowledge, ___much can be learned.
Now we can fly to Tokyo. There was a time ________ we had to take a boat.
The world ______ is made up of matter.
The reason _______ he gives for not coming is that his mother is ill.