Passage Two Questions 29 to 32 are based on the passage you have just heard.

A．After he bought his own print shop.
B．After he signed some historic documents.
C．When he invented the lightning rod.
D．When Pennsylvania Gazette became successful.

A．suggest that self-medication has a long history
B．define what diagnosis means exactly
C．praise doctors for their expertise
D．tell the symptoms from the causes