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

A．Teotihuacan, once the home of 200,000 people, was the center of a large empire.
B．Many archaeologists are fascinated by the ruins of a pre-Columbia city called Teotihuacan.
C．Teotihuacan, once a major metropolitan area, was destroyed by an invasion.
D．A still unsolved mystery is why the people of Teotihnacan suddenly abandoned their city.

A．Future happiness is attractive,
B．The man shouldn’t work too hard for the happiness of future.
C．The man should retire early.
D．Today’ s happiness is less important than tomorrow’s.