Another man-made wonder of the US was built long before the nation was established. About 900 years ago, the Ancestral Puebloan people built villages high in the walls of canyons（大峡谷）in Colorado, where 600 cliff dwellings are now part of the Mesa Verde National Park.    
Visitors can stand at the top and look into the dwellings almost hidden in openings of the rock walls.The Puebloan people cut small steps into the rock, which connected buildings containing hundreds of rooms.
The rock walls have protected the buildings from severe weather in the area; therefore, they remain mostly unchanged in the hundreds of years since they were built.
Our final man-made wonder is in the northwestern city of Seattle, Washington. The Space Needle was built as the central structure for the 1962 World’s Fair.          
The 184-meter-tall structure was designed by Edward Carlson, which has a wide base on the ground, with its middle narrow and a large ring-like structure on top.The structure was meant to look like a “flying saucer,” a vehicle that was popular in science fiction space travel stories. The saucer includes an observation area and eating place.The restaurant slowly turns to provide visitors with a 360 degree view of Seattle.
The Space Needle was not very costly, and was designed and completed in about a year and opened on the first day of the World’s Fair.
Today, the Space Needle is the most popular place for visitors to Seattle. And it remains the internationally known symbol of the city.
What can be talked about before the text?
A. American geography.
B. Touring in the USA.
C. Other US artificial wonders.
D. World natural wonders.
The underlined word “dwelling” is closest in meaning to “________”.

A．houses

B．people

C．canyons

D．steps

The buildings in the rock stay almost unchanged because________.

A．the weather there is severe

B．they were well built

C．people look after them well

D．the rock walls protect them

Which is true of the Space Needle?

A．It remains a symbol of the US.

B．Edward Carlson built the structure.

C．It has a ring-like structure on top.

D．It is a man-made wonder in Colorado.

What is the best title of the text?

A．Cultural Relics	B．Artificial Wonders in the US
C．Symbols of Cities	D．Natural Places in the US