My hometown, Wanzhou, is no longer________ it used to be.
Air, _ __we breathe every day, is around us all the time.
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.