1．How should you tour San Francisco to appreciate its buildings?

　　A．By air　　　　　　　 B．By bus.

　　C．On foot D．By boat

　　C　[推理判断题。根据Tour the City on Foot中"A tour of the city on foot usually focuses on a more localized neighborhood level，which can be very interesting in a number of different ways."可知，应该步行游览旧金山来欣赏它的建筑。故选C。]

　　2．What can we learn about the Waters of San Francisco Bay?

　　A．They have high quality sea water.

　　B．They are explored on a localized level.

　　C．They were not in use until the last century.

　　D．They have helped the city to develop further.

　　D　[推理判断题。根据Hit the Waters of San Francisco Bay中"The waters of San Francisco Bay have played an important role in the city s development over the last century"可知，关于旧金山湾的水域，我们能了解到他们帮助这个城市进一步发展。故选D。]

　　3．Which tour cost most?

　　A．Tour San Francisco From the Air

　　B．Hit the Waters of San Francisco Bay

　　C．Tour the City on Foot

　　D．Take a Bus Tour

　　A　[推理判断题。根据Tour San Francisco From the Air中"While it is one of the most expensive ways to see San Francisco，touring the city from the air is one of the most unique and thrilling ways to see the city."可知，Tour San Francisco From the Air的旅行花费最高。可知答案为A。]

　　4．What is the author's purpose in writing the text?

A．To introduce San Francisco.