A、By different gestures. B、By different voices. C、By different face colours. D、By different names. C对话中女士提到They paint their face

M: I hear that the make-up in Beijing opera is almost an art form in itself, isn’t it?
W: That’s true. Apart from the costumes, the characters are differentiated by their faces.
M: In what way?
W: There are four main types of character: the lead, the female lead, the painted face and the clown. Take a careful look at the actors and see if you can tell which is which.
M: That man there with a white nose is the clown. That beautiful girl is the female lead.
W: That’s right. By the way, how old do you think the actress is?
M: She looks as if she’s in her teens.
W: In fact, she is in her late forties.
M: My goodness. It’s almost unbelievable!
W: That’s where the art comes in Mei Lanfang, a very famous actor, who used to play the role of a young female lead until he was in his seventies.
M: Really? He must be an excellent actor! Well, I can’t tell which the painted face is.
W: There are actually more than one. They paint their faces in different patterns with different colours to reveal their characters. Red stands for loyalty, white for the opposite meaning, and black for uprightness and integrity.
M: Yes, the make-up seems as much fun as the performance.
W: I’m glad you enjoy it.
Questions 9 to 12 are based on the conversation you have just heard.
9. Which is not included in the four main types of character?
10. Which is true according to the conversation?
11. Apart from costumes, how do they differ among the characters in Beijing opera?
12. What does "white" on the painted face stand for?