. _____is known to us all is that the old scientist, for____ life was hard in the past,still works very hard in his eighties.
Washington, a state in the United States, was named ______ one of the greatest American presidents.
—I’ve got an “A” in the examination. —That’s a good ______. You will surely win a second.
In order to learn the _______ of the family business, Bill took a job as messenger boy in one of the offices.
Electricity, like other forms of ______, has greatly increased in price in recent years.
—Hello, I’d like to speak to Henry. —Oh, which _______? There are two ______ in our office.