To bridge the generation gap, （） should realize that the world has changed.

单项选择题One important reason for the difference existing between the young and the old is that （）

A．they live in different ages
B．they live in different countries
C．they live in separate planets
D．they hate each other

单项选择题Which one is the most suitable title for this small piece of article（）

A．The Old World and the New World.
B．Generation Gap.
C．The Good Old Days.
D．The Dead Convention.