A．the forces that influence people’s opinions
B．the freedom of speech in a democratic society
C．the necessity to uphold one’s own opinion on an issue
D．the techniques of talking to a large audience via the mass media

A．Without a prospect of a of at the end of investment, no one would ever lend money to anyone involved in bio-medical research.
B．Private fund is the most important financial source for scientific research.
C．It is commonly agreed that people can dispose their own body organs because of their ownership.
D．Commercial use of body organs is unconstitutional in the US.