47. What would we think of a person who invades our personal space according to the author?

　　A) They are aggressive.

　　B) They are outgoing.

　　C) They are ignorant.

　　D) They are ill-bred.

　　48. How do robots learn human values?

　　A) By interacting with humans in everyday life situations.

　　B) By following the daily routines of civilized human beings.

　　C) By picking up patterns from massive data on human behavior.

　　D) By imitating the behavior of properly brought-up human beings.

　　49. What will a well-programmed robot do when facing an unusual situation?

　　A) Keep a distanc ..........