Which of the following is TRUE according to the passage?A.A patent holder must publicize t
Which of the following is TRUE according to the passage?
A.A patent holder must publicize the details of his invention when its legal period is over.
B.When a patent becomes out of effect, it can be re-patented or extended if necessary.
C.It is necessary for an inventor to apply for a patent before he makes his invention public.
D.One can get all the details of a patented invention from a library attached to the patent office.