Questions 33 to 35 are based on the passage you have just heard.

A．doctor and nurse.
B．Librarian and library patron.
C．Forest ranger and hiker.
D．Nurse and patient.

A．Because we have made up our minds to do so.
B．Because we want to fulfill our desire for knowledge.
C．Because we want to enjoy the ecstasy of achievement.
D．Because we cannot help ourselves.