Science moves forward ,they say, not so much through the insights of great men of genius as because of more ordinary things like improved techniques and tool.

A．lie wasn't able to produce a single book.
B．He hadn't seen a change for the better.
C．He wasn't able to have a rest for a whole year.
D．He didn't make any money.

A．warn young people of the hardships that a successful writer has to experience
B．advise young people to give up their idea of becoming a professional writer
C．show young people it's unrealistic for a writer to pursue wealth and fame
D．encourage young people to pursue a writing career