[单项选择]Despite their varied designs, navigation computers used in cars ______.
A. are more or less the same price.
B. provide directions in much the same way.
C. work on more or less the same principles.
D. receive instructions from the same satellites.

[单项选择]Despite their varied designs, navigation computers used in cars ______.
A. are more or less the same price
B. provide directions in much the same way
C. work on more or less the same principles
D. receive instructions from the same satellites

[单项选择]The navigation computers have one thing in common: they all
A. contain series of maps on videodiscs or videotapes.
B. contain 13,300 maps covering the continental US.
C. can be obtained free of charge.
D. cost a lot of money.

[单项选择]

Navigation computers, now sold by most car-makers, cost $2,000 and up. No surprise, then, that they are most often found in luxury cars, like Lexus, BMW and Audi. But it is a developing technology — meaning prices should eventually drop — and the market does seem to be growing.
Even at current prices, a navigation computer is impressive. It can guide you from point to point in most major cities with precise turn-by-turn directions — spoken by a clear human-sounding voice, and written on a screen in front of the driver.
The computer works with an antenna (天线) that takes signals from no fewer than three of the 24 global positioning system (GPS) satellites. By measuring the time required for a signal to travel between the satellites and the antenna, the car’s location can be pinned down within 100 meters.
The satellite signals, along with inputs on speed from a wheel-speed sensor and direction from a meter, deter- mine the car’s
A. will greatly promote sales of automobiles
B. may help solve potential traffic problems
C. are likely to be accepted by more drivers
D. will soon be viewed as a symbol of luxury

[单项选择]These varied racial groups have learned to live together in peace and ______ , setting an example well worth following.
A. harmony
B. grace
C. rhythm
D. relief