Questions 11 to 18 are based on the conversation you have just heard.

A．External motivation can sometimes bring about negative outcomes.
B．People are likely to do their work without enthusiasm because of threat;
C．Students often study in order to please their parents and teachers.
D．The second form of motivation can be dangerous if the students can’t achieve their own goal.

A．The way to ensure the survival of the human race on Venus.
B．The way to breed organisms on Venus.
C．The way to reduce the population of the Earth.
D．The way to conquer the universe.