The mobile phone is useful to us, and we can use it _______others at any place.A. call B. calling C. to call
-- I’m terribly sorry that I’ve kept you waiting for so long. -- ____________.
I think ____ not difficult ____ English every morning.
____ is said that ____ tourists visit the Great Wall every day.
Great changes ________ since we entered E-times. And the computer is widely used throughout the world.
He _____ with a pencil. Now a pen _____ by him.