The math problem is _____ difficult that only _____students can work it out.
gton, a state in the United States, was named _______ one of the greatest American presidents.
If you don’t go to the meeting tomorrow, ______.
With the touch of a button or the click of a mouse, people will find abundant information from the largest libraries and museums in the world .
What do you think of your math teacher’s lessons—-We all like his classes. He likes telling ______ in class.