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

A．One friend was absent from the party.
B．Not all her friend participated in the party.
C．All her friends were present at the party.
D．All her friend took partners to the party.