Einstein was the Nobel Prize for his work in quantum physics.
The man showed us so heavy a stone ________ no man can lift.
Some pictures of the river brought the days back to the old ________ they swam in it.
Is this research center ________ you visited the modern equipment last year?
The humans are destroying nature day by day, ________ of course, will cause severe punishment from it sooner or later.
The people, ________ had been damaged by the flood, were given help by the Red Cross.