Passage Two
Questions 29 to 31 are based on the passage you have just heard.

A．To demonstrate that saying "Please" and "Thank you" is a good habit.
B．To demonstrate that politeness is the nature of a moral compass.
C．To demonstrate that politeness helps the child get along in the world.
D．To demonstrate that reinforcement is an efficient approach to building positive behavior.

A．they thought that they were kidnapping Mrs. Murdoch
B．they did not know that Mrs. Murdoch was an Australian
C．they did not know that Mrs. McKay had gone to Australia
D．they were paid a million pounds, but still killed their victim