The main topic of this passage can be summarized as______.

A．illustrate the growth of new blogs in number leads to the revolution about blogging
B．demonstrate the number isn't big enough to guarantee the power of the medium
C．show the readers of most blogs are limited to friends and co-workers only
D．indicate ten excellent blogs every day will accumulate to a revolutionary number one day

A．The new products of GM have an excellent sale in 2005.
B．The truck sales of Ford are always superior to the cars.
C．Ford's redesigned Mustang is very popular among the public.
D．The sales of F-Series lineup keep increasing all the way.