The potential of economic development of one region varies from ______ of another.

Within industries，companies are always trying to develop products that are one step better than _____ of other companies．

—How do you find your new classmates, Jim?—Most of them are nice to me, but ______is better to me than Rick.

Generally speaking, clothing made of man-made fibers is less superior than _______ made of natural fibers like cotton, wool or silk.

—Which of the two books will you buy?— I’ll buy _____ of them, because I’m not interested in them.